In fall 2006，the National Basketball Association （NBA）started using basketballs made with synthetic ，or man-made ，material instead of leather（皮革）．They made the change be- cause they wanted every basketball they use to feel and bounce（弹起）the same．Not all leather balls are exactly alike in weight or how they bounce，but the synthetic balls are．

However，some players complained right away that the new balls bounced differently and were actually harder to control than the leather ones．

Physics helped answer questions about why the new balls felt different．For example，the scientists studied friction（摩擦力），which in this case affects the ability of a player to hold onto a ball．"The greater the friction，the better it will stick to his hand，"explains a scientist．

Tests on both wet and dry balls showed that while the synthetic ball was easier to hold onto when dry，it had less friction and became much harder to hold onto when wet．That's because sweat（汗水） stays on the surface of the synthetic balls but gets taken into the leather balls．

The scientists also tested bounce and found that the logo （商标）printed on the new balls made their surface uneven（不平） and caused them to bounce a little strangely com- pared with the leather balls．

In January，the NBA went back to using the leather bails．They aren't perfect，but for now，that's just the way the ball bounces．

1．Why were the synthetic balls expected to be used in NBA according to the text?

       A．Because they are easier to control．           B．Because they waste less material．

       C．Because they look exactly alike．             D．Because they feel and bounce alike．

2．The ball is easier to hold on to_________

A．when friction is greater                    B．when friction is less

C．when it is heavier                         D．when it bounces strangely

3．The synthetic ball bounces differently from the leather one mainly because _________

A．it is wet                                  B．it is dry

C．there's a logo on it                       D．its weight remains the same

4．It can be inferred（推断） from the text that _________．

A．a synthetic ball takes in water faster than a leather ball

B．a leather ball is more difficult to make than a synthetic one

C．a synthetic ball is more expensive than a leather ball

D．a leather ball may increase its weight during a game

5．The underlined word" They" in the last paragraph refers to __________．

A．the synthetic balls                        B．the leather balls

C．the ball players                          D．the scientists

Recently a specialist(专家) in teenager studies does some research on teenage problems. He thinks parents shouldn’t be blamed of themselves because there is nothing they can do to deal with the teenage problem. Whatever they do, sometimes a wonderful, kind and helpful child will turn into a terrible animal.
I’ve seen friends deal with it in all kinds of different ways. One strict mother insisted that her son, should stand up, open doors and shake hands like a gentleman whenever anyone entered the room. I saw him last week when I visited them. Lying on the sofa, he made no attempt to turn off the loud TV he was watching as I walked in. His mother was angry. “I don’t know what to do with him these days,” she said. “He’s forgotten all the manners we taught him.”
He hasn’t forgotten them. He’s just decided that he’s not going to use them. She said that she would like to throw him down from the sofa onto the floor.
Another good friend of mine let her two daughters climb all over the furniture, reach across the table, stare at me and say, “I don’t like your dress, it’s ugly.” One of the daughters has recently been driven out of school. The other has left home.
“Where did we go wrong?” Her parents are now very sad. Probably nothing is wrong with the parents.
【小题1】This text is most probably written by________.

Escaping a fire is a serious matter. Hundreds of people are killed because of fire every year. Knowing what to do during a fire can save your life. It is important to know the ways you can use and show them to everyone in the family, such as stairways or windows escapes, but not elevators.

From the lower floors of the buildings,    62     . it is the best way of leaving by windows with the least chance of serious injury.

The second floor window is usually not very high from the ground. A middle build person, hanging by the fingertips will have a drop of about six feet to the ground,     63     .Of course, it is safer to jump a short way than to stay in a burning building.

Windows are also useful when you are waiting for help. Be sure to keep the door closed,      64     __. Keep our head low at the window to be sure you get fresh air rather than smoke that may leak into the room.

On a second or third floor, the best windows for escape are those that open onto a roof.        65     .Dropping onto cement（水泥） might end in injury. Bushes and grass can help to break a fall.