其他

单萜类是由（  ）个异戊二烯单位构成，含10个碳原子的化合物类群。 A:1 B:...

香豆素类都具有（  ）基本骨架。 A:苯醌母核 B:苯骈呋喃 C:苯骈α-吡喃酮...

一般情况下，黄酮、黄酮醇及其苷类多显（  ）色。 A:黄～橙 B:灰黄～黄 C:...

It is our ________ policy that we will achieve uni...

Between 1974 and 1997, the number of overseas visi...

Everybody ________ in the hall where they were wel...

Young people are not ________ to stand and look at...

The words of his old teacher left a ________ impre...