In the fall 2006, the National
Basketball Association (NBA) started using basketballs made with synthetic, or
manmade material instead of leather. They made the switch because they wanted
every basketball they use to feel and bounce the same. However,
some players complained right away that the new balls bounced differently and
were actually harder to control than leather ones. Dallas Mavericks owner Mark
Cuban asked for help the Department of Physics at the University of Texas. The
scientists investigated friction that affects the ability of a player to hold
onto a ball. "The greater the friction, the better it will stick to his hand,"
explains Horwitz, one of the physicists who worked on the project.
Tests on both wet and dry balls showed that while the plastic ball was
easier to grip when dry, it had less friction and became much harder to hold
onto when wet. That's because sweating stays on the surface of the synthetic
balls but gets absorbed into the leather balls--an important detail for sweaty
athletes. In January, the NBA went back to use the traditional
leather balls. They aren't perfect, but for now, that's just the way the ball
bounces.
单选题
The NBA started using synthetic basketballs instead of leather ones because ______.
【正确答案】
D
【答案解析】[注释] 本题的关键是找到文章中的依据句：“They made the switch because they wanted every basketball they use to feel and bounce the same．”只需对照该句话与选项在用词和意思方面的一致性就可以确定正确答案。
单选题
How did some NBA players respond to the switch to synthetic balls?
【正确答案】
A
【答案解析】[注释] 参考题干上的主语some players，可以很容易找到文章第二段第一句话就是本道题的依据句。其后半句话的中心意思是说“新球弹力不同，并且实际上比皮球更难控制”。逐一分析选项：B选项侧重点有错，正确说法应为“They felt differently about the new／synthetic balls．”；C选项中的comfortable意思与原句意思相反；D选项的意思没有涉及。所以，A选项(“他们认为新球没有原来的皮球好。”)意思与原句最为接近，为最佳答案。
单选题
Which of the following contributes to the better control of the balls?
【正确答案】
C
【答案解析】[注释] 第二段最后一句话“The greater the friction，the better it will stick to his hand，” 为本题的依据句，C项答案非常明确。而其他的选项内容在依据句中没有涉及，均属于无关信息。
单选题
When is it harder for an NBA player to hold onto a synthetic ball?