问题 单项选择题

古人把东、北、西、南四方每一方想象为四种动物形象,叫做四象。四象在中国传统文化中指青龙、白虎、朱雀、玄武,分别代表东西南北四个方向。它源于中国古代的()。

A.图腾崇拜

B.远古传说 

C.炼丹术

D.星宿信仰

答案

参考答案:D

解析:

四象在中国传统文化中指青龙、白虎、朱雀、玄武,分别代表东西南北四个方向,源于中国古代的星宿信仰。在二十八宿中,四象用来划分天上的星星,也称四神、四灵。“四象”是古人把每一个方位的七宿联系起来加以想象而成的四种动物的形象。

选择题
单项选择题

In fall 2006, the National Basketball Association (NBA) started using basketballs made with synthetic, or man-made, material instead of leather. They made the change because they wanted every basketball they use to feel and bounce 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, 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 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 printed on the new balls made their surface uneven and caused them to bounce a little strangely compared with the leather balls.
In January, the NBA went back to using the leather balls. They aren’t perfect, but for now, that’s just the way the ball bounces.

It can be inferred 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