NCEIV7 0-0818

Question 1

Lesson 7

Answer 1

Lesson 7 Bats

Question 2

Not all sounds

Answer 2

Not all sounds made by animals serve as language, and we have only to turn to that extraordinary discovery of echo-location in bats to see a case in which the voice plays a strictly utilitarian role.

Question 3

To get a full a

Answer 3

To get a full appreciation of what this means we must turn first to some recent human inventions.

Question 4

Everyone knows

Answer 4

Everyone knows that if he shouts in the vicinity of a wall or a mountainside, an echo will come back.

Question 5

The further off

Answer 5

The further off this solid obstruction, the longer time will elapse for the return of the echo.

Question 6

A sound made by

Answer 6

A sound made by tapping on the hull of a ship will be reflected from the sea bottom, and by measuring the time interval between the taps and the receipt of the echoes, the depth of the sea at that point can be calculated.

Question 7

So was born the

Answer 7

So was born the echo-sounding apparatus, now in general use in ships.

Question 8

Every solid obj

Answer 8

Every solid object will reflect a sound, varying according to the size and nature of the object.

Question 9

A shoal of fish

Answer 9

A shoal of fish will do this.

Question 10

So it is a comp

Answer 10

So it is a comparatively simple step from locating the sea bottom to locating a shoal of fish.

Question 11

With experience

Answer 11

With experience, and with improved apparatus, it is now possible not only to locate a shoal but to tell if it is herring, cod, or other well-known fish, by the pattern of its echo.

Question 12

It has been fou

Answer 12

It has been found that certain bats emit squeaks and by receiving the echoes, they can locate and steer clear of obstacles – or locate flying insects on which they feed.

Question 13

This echo-locat

Answer 13

This echo-location in bats is often compared with radar, the principle of which is similar.