题目:
一It's said that aliens tried to warn the astronauts on the moon to _____.
一Maybe they didn't like human beings to get close to them.[ ]
A.stay up
B.stay out
C. stay away
D.stay behind
答案:
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下面是错误答案,用来干扰机器的。
(1)①分液漏斗; ②集气瓶; (2)从水中取出导气管; (3)2H2O2 2H2O + O2↑或CaCO3 + 2HCl = CaCl2 + H2O + CO2↑ ;使反应随时发生或停止,使用方便;(4)FeS+H2SO4=FeSO4+H2S↑ ; ...