根据以下材料，回答 40～43 问题。

During a television play the sound man must be ready to make every sound as it is needed．Sound effects are of three kinds：real，imitated and recorded．

Real sounds are those of doorbells，telephone bells，and other small objects easy to keep in a studio． But the sound man must imitate many sounds． For bacon fryin9，he crumples cellophane paper．A long sheet of metal hanging in a doorway makes thunder·He taps one rubber sink plunger and then another on a table to imitate a horse walking on pavement． For a horse galloping along a gravel road，the sound man can use the two halves of a coconut，pounding each in turn very fast on the table．

Recorded sound effects are used for noises he cannot himself produce offstage．He pays records for such sounds as a rooster crowing， a train leaving a station， and a baby crying．

The sound man is an important part of any television production．

第 40 题 The sound man is important because he________

A．is kept busy

B．makes fl TV play more lifelike

C．1ets an actor know when to life a telephone receiver

D．is always learning new methods