已知sin(-x)=,则sin2x的值为___________________.
My sister, who has no clear sense of direction, was at __________ loss when finding that __________ road she used to go along was in repair. A. a; a B. / ;
“红色荒漠”是指我国南方低山丘陵地区的土地荒漠化，植被覆盖率在30%以下。下图为“红色荒漠”形成结构示意图。据此回答7～8题。 7．图中①②
Susan 1ikes_______ very much．She gets up early and runs with her father every day A．art B．music C．sports D．computer
A huge shire horse in Australia has been declared the biggest horse in the world by its owner , beating the current Guinness World Record（吉尼斯记录） by several inches . The huge five-ye
维通橡胶是一种耐腐蚀、耐油、耐高温、耐寒性能都特别好的氟橡胶。它的结构简式为：。合成它的单体为 A．氟乙烯和全氟异丙烯
（09西安一中第一次月考）在证明DNA是遗传物质的几个著名经典实验中，在实验设计思路中最关键的是A．要用同位素标记DNA和蛋白质 B．要得到
如图所示是将一光敏电阻接入多用电表两表笔上，将多用电表的选择开关置于欧姆挡，用光敏电阻时，表针的偏角为；现用手掌挡住部分光线，表针的
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