A linguist, who studies languages, is always listening, never off-duty. I invited a group of friends to my house, telling them that I was going to record their speech. I said I was interested in their regional accents (地方口音), and it would take only a few minutes to record it. Afterwards, one evening, three people came to my house and were shown into my sitting-room. In front of each chair there was a microphone (麦克风) at head height, connected to a recorder in the middle of the floor. They sat down rather nervously. I explained that all I wanted was for them to count from one to twenty, then we could relax and have a drink.
I turned on the recorder and they each in turn counted from one to twenty in their best accents. When it was over, I turned the recorder off and brought round the drinks. The rest of the evening was spent in complete relaxation. I talked and joked with them freely and left them  for a telephone call which lasted some time.
You know, of course, the microphones were not connected to the recorder in the middle of the room at all but to another one in the bedroom. My friends, having seen the recorder before them turned off, paid no more attention to the microphones a few inches from their mouths, thus giving excellent sound quality (质量). It meant that I was able to get a piece of natural talk.
I should add, perhaps, that I did tell my friends what had happened to them after the recording was over, and asked them whether it should be destroyed. None of them wanted to – but for some years after that, it always seemed that when it came to buying drinks, I paid for them. Linguistic research can be a very expensive business.
The underlined word "linguist" in Paragraph 1 probably means "   ".

A．people who learn to speak languages.

B．people who do research on languages.

C．people who speak languages.

D．people who develop languages.

The recording which the writer was able to make was   .

A．natural.	B．beautiful
C．unclear.	D．nervous.

When the writer told his friends what he had done, they   .

A．wanted him to destroy records

B．didn't seem to mind much

C．seemed to have no response (反应)

D．made him buy them more drinks