【简答题】A mouse looked through a crack in the wall to see the farmer and his wife opening a package: What food might it contain? He was astonished to discover that it was a mouse trap! Retreating to the farmy...
【单选题】下列应用特征现象推断不正确的是( )
A.
遇FeCl 3 溶液显紫色或加入溴水产生白色沉淀,表示物质中可能含有酚羟基。
B.
加入新制Cu(OH) 2 悬浊液并加热,有红色沉淀生成,或加入银氨溶液并水浴加热有银镜出现,说明该物质中含有—CHO
C.
加入金属钠,有H 2 产生,表示物质可能有—OH或—COOH
D.
加入NaHCO 3 溶液有气体放出或能使紫色石蕊试液变红,表示物质中含有—COOH
【简答题】现有下列物质:①乙炔②苯酚溶液③乙醛④淀粉溶液⑤氨基酸.请回答: (1)遇碘水呈蓝色的是______(填序号,下同). (2)能发生成肽反应的是______. (3)能跟溴发生加成反应的是______. (4)能跟银氨溶液发生银镜反应的是______. (5)能跟饱和溴水反应生成白色沉淀的是______.
【简答题】读寓言故事,然后回答问题。 Cat: I'm hungry. Hmm... Here comes a mouse. Now I can catch it. Mouse: Dear cat. Wait a minute. Don't eat me. I can do things for you. Cat: Oh! What can you do? Mouse: I can sing. Cat: C...
【单选题】I can ride a ___________. [ ]
【简答题】现有下列物质:①乙炔 ②苯酚溶液 ③乙醛 ④淀粉溶液 ⑤氨基酸。请回答: (1)遇碘水呈蓝色的是 (填序号,下同)。 (2)能发生成肽反应的是 。 (3)能跟溴发生加成反应的是 。 (4)能跟银氨溶液发生银镜反应的是 。 (5)能跟饱和溴水反应生成白色沉淀的是 。
【简答题】猜猜看,他们都是谁? 1. I look like a mouse, but I'm not a mouse. I have a thick (厚的) tail (尾巴). A squirrel 2. I look like a pig, but I'm not a pig. I have a long nose. ______________
【判断题】零件图中的一组尺寸不可能提供制造和检验零件所需的全部尺寸