“APS-C”的画幅为?()
A.24mm*16mm
B.24mm*20mm
C.24mm*26mm
D.24mm*30mm
参考答案:A
根据语篇内容,用恰当的短语填空,使之意思完整。
Thanks for your invitation. I'm sorry I can't visit you this week. I am __1__. This evening I'm going
to my cousin's house. It's my cousin's birthday. Today I have a toothache, so I have to see the dentist
tomorrow. On Friday, there will be a math test, and I __2__. On Friday evening, a new film will be on,
and I'm __3__ with my friends.
150℃时,只含C、H、O三种元素的有机物A 8.8 g 在一定量的O2中燃烧,生成的混合气体缓慢通过盛有足量无水CuSO4的干燥管,干燥管中的固体增重10.8g,剩余的气体通入盛有足量澄清石灰水的试剂瓶,试剂瓶中的物质增重8.8g,最后的气体缓慢通过盛有灼热CuO的硬质试管,硬质试管中的物质质量减少4.8g.请通过计算和分析回答下列问题:
(1)写有机物的分子式______
(2)本题中,A和O2反应的化学方程式为______;
(3)若A的结构满足下列条件:能和Na反应但不能和NaOH反应;能进行催化氧化但不能发生消去反应.则A的结构简式为______.