阅读理解。
Parents often believe that they have a good relationship with their teenagers (青少年). But last summer,
Joanna and Henry noticed a change in their elder son: suddenly he seemed to be talking far more to his friends
than to his parents. "The door to his room is always shut." Joanns noted.
Tina and Mark noticed similar changes in their 14-year-old daughter. "She used to cuddle up (蜷伏) with
me on the sofa and talk," said Mark. "Now we joke that she does this only when she wants something,
Sometimes she wants to be treated like a little girl and sometimes like a young lady. The problem is figuring
out which time is which."
Before age 11, children like to tell their parents what's on their minds. "In fact, parents are first on the list."
said Michael Riera, author of Uncommon Sense for Parents with Teenagers. "This completely changes during
the teen years." Riera explained. "They talk to their friends first, then maybe their teachers, and their parents
last."
Parents who know what's going on in their teenagers'lives are in the best position to help them. To break
down the wall of silence, parents should create chances to understand what their children want to say, and try
to find ways to talk and write to them. And they must give their children a mental break, for children also need
freedom, though young. Another thing parents should remember is that to be a friend, not a manager, with
their children is a better way to know them.
1. "The door to his room is always shut" suggests that the son _____.
A. is always busy with his studies
B. doesn't want to be disturbed (打扰)
C. keeps himself away from his parents
D. begins to dislike his parents
2. What troubles Tina and Mark most is that _____.
A. their daughter isn't as lovely as before
B. they can't read their daughter's mind exactly (确切地)
C. they don't know what to say to their daughter
D. their daughter talks with them only when she needs help
3. Which of the following best explains "the wall of silence" in the last paragraph?
A. Teenagers talk a lot with their friends.
B. Teenagers do not want to understand their parents.
C. Teenagers do not talk much with their parents.
D. Teenagers talk little about their own lives.
4. What can be learned from the passage?
A. Parents are unhappy with their growing children.
B. Parents have suitable ways to talk with their teenagers.
C. Parents should be patient with their silent teenagers.
D. Parents should try to understand their teenagers.
可以被KMnO4的酸性溶液氧化成
，但若烷基R中直接与苯环连接的碳原子上没有C-H键，则不容易被氧化得到
，现有分子式是C11H16的一烷基取代苯，已知它可以被氧化为
的异构体有七种，其中的三种是： 