【判断题】古法印制的照片在阳光下会变色,因此要避光保存。
【判断题】古法印制的照片在阳光下会变色,因此要避光保存。()
【单选题】公元前 501 年,自己制作了一部“竹刑”的郑国人是 ( )?
【简答题】People are talking about the “new economy.” It’s very different from the “old economy”. In the old economy, people travel to work. They buy things in stores. They use the post office, the fax and the ...
【简答题】What's the passage mainly about? A) development of economy B) recovery of economy C) expansion of economy D) prosperity of economy
【判断题】古法印制的照片在阳光下会变色,因此要避光保存。
【简答题】由某饱和一元醛和饱和一元酮(通式为C n H 2n O, n≥3,分子中含有羰基,但不能被弱氧化剂氧化)组成的混合物共0.5 mol,其质量为23.4g,此混合物与足量银氨溶液反应,析出86.4g银。推断混合物的可能组成及质量。