To clean drinking water

Question 1

contrary (adj.) [4 meanings]

Answer 1

1: exactly opposite to something else : entirely different from something else
2: against or opposed to something — often + to
3: not favorable or helpful
4: unwilling to obey or behave well

Question 2

dentures (n.) [1 meaning]

Answer 2

a set of artificial teeth — usually plural

Question 3

purify (verb) [2 meanings]

Answer 3

1: to remove dirty or harmful substances from (something)
2: to free (someone) from guilt or evil thoughts

Question 4

crud (n.) [2 meanings]

Answer 4

1: a dirty or greasy substance

2 (chiefly US): something unpleasant or worthless

Question 5

nasty (adj.) [5 meanings]

Answer 5

1: very unpleasant to see, smell, taste, etc.
2: indecent and offensive
3: unpleasant and unkind
4: very bad or unpleasant
5: very serious or severe; causing much damage

Question 6

strain (n) [5 meanings]

Answer 6

1a: a feeling of stress and worry that you have because you are trying to do too much, are dealing with a difficult problem, etc.
b: something that is very difficult to deal with and that causes harm or trouble
c: a force that pulls or stretches something : stress
d: an injury to a body part or muscle that is caused by too much tension, effort, or use
2: a group of closely related plants or animals : variety — often + of

Question 7

membrane (n.) [2 meanings]

Answer 7

: a thin sheet or layer

especially : a thin sheet or layer of tissue that is part of a plant or an animal’s body

Question 8

filter (v.) [4 meanings]

Answer 8

1 [+ object] a : to pass (something, such as a gas or liquid) through a a device that is used to remove something unwanted from a liquid or gas that passes through it
b : to remove (something unwanted) by using such a device — often + out — often used figuratively
2 always followed by an adverb or preposition [no object] a : to move through or into something in small amounts or in a gradual way
b : to come or go slowly in small groups or amounts

Question 9

relatively (adv.) [1 meaning]

Answer 9

when compared to others

Question 10

flow (v.) [6 meanings]

Answer 10

1 (of liquid, gas, or electricity): to move in a steady and continuous way — often used figuratively
2 a: to move in a continuous and smooth way
b: to move, come, or go continuously in one direction
3 a: to proceed in a smooth and easy way
b of a drink : to be drunk freely [=people drank wine throughout the evening]
4: to hang down in a loose and graceful way (as in hair over shoulders)
5: to be caused or produced by something : to come from something (as in wealth from trade)
6 (of a tide): to move in toward the land : rise

Question 11

bulb (n.) [3 meanings]

Answer 11

1: a glass tube that produces light when it is supplied with electricity
2: a rounded part of some plants that is under the ground and that grows into a new plant during the growing season
3: a part that has a rounded shape

Question 12

tissue (n.) [2 meanings]

Answer 12

1 [count or non-count]: a piece (or mass) of soft and very thin paper that is used especially for cleaning
2: the material that forms the parts in a plant or animal
[noncount, can be plural]

Question 13

sap (noun and verb) [2 nominal and 2 verbal meanings]

Answer 13

NOUN
1 [noncount]: a watery juice inside a plant that carries the plant’s food
2 [count] chiefly US, informal : a person who is easily tricked or cheated
VERB
1: to use up the supply of (something, such as a person’s courage, energy, strength, etc.)
2: to cause (someone) to lose courage, energy, strength, etc. — usually + of

Question 14

root(s) (n.) [8 meanings]

Answer 14

1 [count]: the part of a plant that grows underground, gets water from the ground, and holds the plant in place
2 [count]: the part of a tooth, hair, fingernail, etc., that is attached to the body
3 [count] a: the cause or source of something — usually singular
b : the origin of something — usually plural (like of rock ‘n roll music)
4 (usually plural) a: the family history of a person or a group of people
b : a special connection to something — + in
5 [count] (mathematics): a number that is multiplied by itself a certain number of times to produce another number
6 [count] : a word from which other words are formed

Question 15

evaporate (v.) [2 meanings]

Answer 15

1: to change from a liquid into a gas
2: to go away suddenly : to disappear or vanish

Question 16

straw (n) [2 meanings]

Answer 16

1 a [noncount] : the dry stems of wheat and other grain plants
— often used before another noun
b [count] : a single dry stem of a grain plant
2 [count] : a thin tube used for sucking up a drink

Question 17

suck (v.) [9 meanings]

Answer 17

1 a [+ object]: to pull (liquid, air, etc.) into your mouth especially while your lips are forming a small hole
sucking milk through a straw
b : to pull on (something in your mouth) with the muscles of your lips and mouth [+ object]
c : to let (something, such as candy or medicine) stay in your mouth as it melts [+ object] [no object: + on]
2 always followed by an adverb or preposition [+ object] a : to pull (something) with the force of moving water, air, etc.
b : to remove (something) from an area or substance by pulling it with the force of moving water, air, etc.
3 [+ object] : to make (part of your body) flatter or tighter by pulling your muscles inward — + in
4 [+ object] : to cause (someone) to become involved or interested in something — + in or into
5 not used in progressive tenses [no object] informal + sometimes impolite
a : to be very bad or unpleasant
b : to do something very badly

Question 18

cavitation (n.) [3 meanings]

Answer 18

1 a: the formation of partial vacuums in a liquid by a swiftly moving solid body (such as a propeller) or by high-intensity sound waves
also : the pitting and wearing away of solid surfaces (as of metal or concrete) as a result of the collapse of these vacuums in surrounding liquid
b: the formation of cavities in an organ or tissue especially in disease

Question 19

invent (v.) [2 meanings]

Answer 19

1: to create or produce (something useful) for the first time
2: to create or make up (something, such as a story) in order to trick people

Question 20

pore (n. and verb) [2 nominal meanings and 1 verbal meaning]

Answer 20

NOUN
1: a very small opening on the surface of your skin that liquid comes out through when you sweat
2: a small opening on the surface of a plant, a rock, etc.
VERB
1. (+over) to read or study (something) very carefully

Question 21

mechanism (n.) [3 menaings]

Answer 21

1: a piece of machinery : a mechanical part or group of parts having a particular function
2: a process or system that is used to produce a particular result
3: a way of acting, thinking, or behaving that helps or protects a person in a specified way (as in, for ‘coping’ or ‘defense’)

Question 22

prevent (v.) [2 meanings]

Answer 22

1: to stop (something) from happening or existing
2: to make (someone or something) not do something : to stop (someone or something) from doing something

Question 23

spread (v.) [11 meanings]

Answer 23

1. [+ object] a : to open, arrange, or place (something) over a large area — often + out
   b : to place (things) over a large area
   2 a [no object] : to become larger or to affect a larger area : to move into more places
   b [+ object] : to cause (something) to be present in more places throughout a large area
   3 a [no object] : to pass from person to person
   b [no object] : to become known by many people
   c [+ object] : to cause (something) to become known by many people
   4: to move (parts of your body) outward or away from each other [+ object] — often + out [also + no object]
   5 [no object] of a smile or other facial expression : to appear and slowly grow more apparent
   6 [+ object] : to put a layer of (something) on top of something else
   7 [+ object] : to divide up (something) over a period of time or among members of a group — often + out

Question 24

setup (n.) [4 meanings]

Answer 24

1: the process of making something (such as a machine or computer program) ready to be used — often used before another noun
2 [count] : the way that something is done or organized
3 [count] informal : a situation in which someone is deliberately put in a bad position or made to look guilty — usually singular
4 [count] : the beginning of a story, joke, etc., that explains and leads to what follows — usually singular

Question 25

peel (v.) [4 meanings]

Answer 25

1 [+ object]: to remove the skin from (a fruit, vegetable, etc.) 2 (always followed by an adverb or preposition) [+ object] : to remove (a covering, shell, etc.) from something — often + from — often + off 3 [no object] a : to come off in pieces b : to lose an outer layer of skin, bark, etc.

Question 26

bark (noun and verb) [2 nominal and 2 verbal meanings]

Answer 26

``` NOUN 1: the outer covering of a tree 2: the short, loud sound made by a dog also : a similar sound VERB 1 [no object] of a dog : to make a short loud sound 2: to shout or say (something) in a loud and angry way [+ object] ```

Question 27

pine (noun and verb) [2 nominal and 2 verbal meanings]

Answer 27

NOUN 1 [count] : a tree that has long, thin needles instead of leaves and that stays green throughout the year 2 [noncount] : the wood of such a tree that is often used to make furniture VERB 1: to become thin and weak because of sadness or loss — usually + away 2: to want or desire (someone or something) very much — + after

Question 28

sapwood (n.) [1 meaning]

Answer 28

: the younger softer living or physiologically active outer portion of wood that lies between the cambium and the heartwood and is more permeable, less durable, and usually lighter in color than the heartwood

Question 29

tube (n.) [6 meanings]

Answer 29

1 [count] a : a long, hollow object that is used especially to control the flow of a liquid or gas b : an object shaped like a pipe 2 [count] : a soft, long, narrow container that has a small opening at one end and that contains a soft material which can be pushed out by squeezing 3 [count] : a thin, long, hollow part within an animal or plant 4 US, informal : the television [=(Brit) the box] 5 [noncount] British : the system of trains that run underground in London

Question 30

leaf (noun and verb) [4 nominal meanings and 1 verbal meaning]

Answer 30

NOUN 1: one of the flat and typically green parts of a plant that grow from a stem or twig 2 [count] : a sheet of paper in a book : page — usually used figuratively 3 [count] : a part that can be added to or removed from a table to change the size of its top surface 4 [noncount] : a very thin sheet of metal (such as gold or silver) that is used to decorate something VERB 1: (+ through) to turn the pages of (a book, a magazine, etc.)

Question 31

stream (v.) [5 meanings]

Answer 31

1 always followed by an adverb or preposition, [no object] : to move in a steady flow 2 (of the body or a body part) a : to produce a liquid continuously and often in large amounts — usually + with 3 (always followed by an adverb or preposition, [no object] : to come or flow continuously to a place in large numbers 4 [no object] : to move freely in one direction especially in wind or water 5 [+ object] British : to group students in a particular grade according to their abilities and needs : track

Question 32

particle (n.) [4 meanings]

Answer 32

[count] 1 a : a very small piece of something b : a very small amount of something 2 (physics): any one of the very small parts of matter (such as a molecule, atom, or electron) 3 (grammar): an adverb or preposition that when combined with a verb creates a phrasal verb

Question 33

attractive (adj.) [2 meanings]

Answer 33

1: having a pleasing appearance especially : having a pleasing appearance that causes romantic or sexual feelings in someone : good-looking 2: having a feature or quality that people like — often + to

Question 34

hurdle (n.) [2 meanings]

Answer 34

1 [count] : one of a series of barriers to be jumped over in a race 2 [count] : something that makes an achievement difficult

Question 35

scale (verb and noun) [3 verbal meanings and 8 nominal meanings]

Answer 35

VERB 1: [+ object]: to climb to the top of (something) — sometimes used figuratively 2: (+ something + back/down [phrasal verb]): to decrease the size, amount, or extent of (something) 3: (+ something + up [phrasal verb]): to increase the size, amount, or extent of (something) NOUN 1: a device that is used for weighing people or things 2: one of many small thin plates that cover the bodies of some animals (such as fish or snakes) 3 [count] : a series of musical notes that go up or down in pitch 4 [count]: a line on a map or chart that shows a specific unit of measure (such as an inch) used to represent a larger unit (such as a mile) : the relationship between the distances on a map and the actual distances 5 [count]: a range of numbers that is used to show the size, strength, or quality of something — usually singular (e.g., from 1 to 10) 6 [count]: a range of levels of something from lowest to highest 7 [noncount] — used to describe a model, drawing, etc., in which all of the parts of something relate to each other in the same way that they do in the larger form 8 [singular] : the size or level of something especially in comparison to something else

Question 36

expect (v.) [5 meanings]

Answer 36

1 [+ object] : to think that something will probably or certainly happen — often followed by to + verb 2 [+ object]: to think that (someone or something) will arrive or that (something) will happen 3 [+ object]: to consider (something) to be reasonable, required, or necessary 4 (always used in progressive aspect) [no object] : to be pregnant : to be due to give birth 5 [+ object] informal : to suppose or think — usually used after I

Question 37

demonstrate (v.) [4 meanings]

Answer 37

1 [+ object] a : to prove (something) by showing examples of it : to show evidence of (something) b : to prove (something) by being an example of it : to be evidence of (something) 2 [+ object]: to show (a quality, feeling, etc.) clearly to other people 3 [+ object] : to show or explain how something is used or done : to show or explain the function or use of (something) 4 [no object] : to take part in an event in which people gather together in order to show that they support or oppose something or someone

Question 38

application (n.) [8 meanings]

Answer 38

1 a: a formal and usually written request for something (such as a job, admission to a school, a loan, etc.) b [count]: a document that is used to make a formal request for something 2a: the act of putting something on a surface, a part of the body, etc. b: the use of an idea, method, law, etc., in a particular situation or for a particular purpose c [noncount] : the use of a word, name, etc., to describe someone or something 3: the ability to be used for practical purposes 4 [count] computers : a computer program that performs a particular task (such as word processing) 5 [noncount] formal : effort made to work hard in order to complete something successfully