碳酸二甲酯的应用主要有哪些方面?
参考答案:
①DMC代替光气作羰基化剂合成异氰酸酯
②DMC作甲基化剂
③新产品开发
④用作汽油添加剂和溶剂
-Lisa, you should not _________ people when they're in trouble.
-OK. I will not do it again, Mum.[ ]
A.laugh at
B.look at
C.shout at
D.smile at
属于α葡萄糖甘酶抑制剂的是()
A.阿卡波糖
B.二甲双胍
C.罗格列酮
D.西格列汀
E.格列吡嗪