阅读短文，选择正确的答案。
One day, after school, Steven asks Bob a question, " Bob, my mother and father have one son, but I
have no brothers and sisters. Who is it? " Bob thinks it over. But he doesn't know the answer. So he has
to ask Steven the answer. Steven laughs and says, " Of course, it's me. "
Next day, Bob asks his father the same question, " Dad, you and my mother have one son, but I have
no brothers and sisters. Who is it? " His father answers, " I'm sorry, I don't know." Bob says happily, " Of
course, it's Steven." Oh, stupid Bob!
1. Bob and Steven are .[ ]
A. brothers
B. sisters
C. classmates
2. asks the same question again. [ ]
A. Steven
B. Bob
C. Father
3. Steven is a boy. [ ]
A. clever
B. worse
C. happy
4. Bob's answer is . [ ]
A. left
B. right
C. wrong
5. How many daughters do Steven's father and mother have?[ ]
A. 0.
B. 1.
C. 2.