Miss Gorgers taught physics in a New York school. Last month she explained to one of her classes about sound, and she decided to test them to see how successful she had been in her explanation. She said to them, “Now I have a brother in Los Angeles. If I was calling him on the phone and at the same time you were 75 feet away, listening to me from the street, which of you would hear what I said earlier, my brother or you and for what reason?”
Tom at once answered, “Your brother. Because electricity travels faster than sound waves.” “That’s very good.” Miss Gorgers answered, but then one of the girls raised her hand, and Miss Gorgers said, “Yes? Kate.”
“I disagree. Your brother would hear you earlier because when it’s 11 o’clock here and it’s only 8 o’clock in Los Angeles.” Kate said.

Miss Gorgers was teaching her class         .

A．how to telephone

B．about electricity

C．about time zone

D．about sound

Miss Gorgers raised this question because she wanted to know whether         .

A．it was easy to phone to Los Angeles

B．her student could hear her from 75 feet away

C．her students had understood her lesson

D．sound waves were slower than electricity

Kate thought Tom was wrong because         .

A．clocks in Los Angeles showed a different time from those in New York

B．electricity was slower than sound waves

C．Tom was not good at physics at all

D．Tom’s answer had nothing to do with sound waves

Whose answer do you think is correct according to the laws of physics?
A. Tom’s.   　 　 B. Kate’s.        C. Both A and B. 　 　D. Neither A nor B.