阅读短文，回答问题。
Who Is Clever?
Miss Helen taught physics in a school of London. Last week she was explaining to her classes about sound,
and then she decided to test them to see how successful she had been in her work. She said to them, "Mow, I
have a sister in New York. If I was calling her on the telephone, and at the same time you were 20 metres away,
and listened to me from the other side of the street. Who do you think would hear what I said earlier, my sister
or you, and why?"
One of the cleverest boy answered at once, "Your sister, Miss Helen, because electricity travels faster than
sound waves."
"That's very good," Miss Helen said. But then one of the girls put up her hand, and Miss Helen said, "Yes,
Molly." "I don't think so," Molly said. "Your sister would hear you later because when it's eleven o'clock here,
it's only six o'clock in New York."
1. Miss Helen was explaining about _______. [ ]
A. telephone
B. electricity
C. time
D. sound
2. Helen's sister is in _______. [ ]
A. London
B. England
C. Washington
D. New York
3. Who can hear Miss Helen earlier according to the boy's answer? [ ]
A. Helen's sister
B. the boy
C. Molly
D. the student
4. Molly thought _____ would hear earlier. [ ]
A. Helen
B. Helen's sister
C. the student
D. nobody
5. When it's seven o'clock in London, it's ______ o'clock in New York. [ ]
A. two
B. six
C. three
D. twelve