A:16
B:13
C:12
D:23
已知CH3C18OOH在水溶液中存在以下平衡:CH3C18OOH⇌CH3CO18OH,当 CH3C18OOH与CH3H2OH发生酯化反应时,写出含18O的所有产物的结构简式: ____
His cousin hardly has vegetables these days, __________?
Students should be encouraged____(present) their own opinions, whether right or wrong.
识图:
请回答:
请根据所提示的内容,补全对话。
A:Look! What ____ it?
B:It’s a ____ .
A:Its ears are ____ .
B:Yes, its tail is ____ .
A:I like ____ .
B:Me too.