一般分离极性大的化合物可用()
A.吸附色谱
B.离子交换色谱
C.聚酰胺色谱
D.正相分配色谱
E.凝胶色谱
参考答案:D
根据所给情景,选择正确的英文表达。
1.你想看看吉姆的吉他,你说: [ ]
A. Is this a guitar?
B. Can I have a look at your guitar?
C. Do you play the guitar?
2. 在商店里购物,你想知道这件物品多少钱,你问: [ ]
A. What about this one?
B. What colour is it?
C. How much is it?
3. 询问别人想要点什么,你说: [ ]
A. What would you like?
B. What do you like?
C. What is this?
下列有关原始社会的叙述,不正确的是[ ]
A.人类最初经历的是原始社会
B.晚期智人出现的同时,现代人种的差异也显现出来
C.氏族的发展先后经历了父系氏族和母系氏族两个阶段
D.在父系氏族社会里,人们“既知其父,又知其母”