现代生活中，光污染已经给人类的生活和身体带来了极大的危害。据光学专家研究，镜面建筑物玻璃的反射光比阳光照射更强烈，其反射率高达82%到90%
为了探究弹簧弹力F和弹簧伸长量x的关系，某同学选了A、B两根规格不同的弹簧进行测试，根据测得的数据绘出如图所示的图象，从图象上看，该同学没
唐朝对东亚、西亚均产生影响的是 ( ) A.政治制度 B.科学技术 C.土地制度 D.儒家思想
No sooner _____ they rushed out into the street. A. did they hear the news thanB. had they heard the news than C. did they hear the news whenD. had they heard the news when
—I’m really sorry, I couldn’t do it better. —Never mind. ________ you have tried your best. A. In all B. After all C. At all
如图20所示，R1、R2为定值电阻，R3为滑动变阻器。3个电阻采用如图（a）方式接在电源上，已知R1＝3Ω、R2＝12Ω。现利用电压传感器（相当于电压表）和
I think that ____ very difficult to learn. the politics is B. politics is C. politics are D. the politics are
摘除子宫的女性不能再生育，是因为子宫（ ） A.能产生卵细胞并分泌雌性激素 B.是形成受精卵的场所 C.是孕育胎儿的场所 D.能分泌营养物质，有利
