硅胶作为吸附剂用于吸附色谱时其为
A．非极性吸附剂B．极性吸附剂C．两性吸附剂D．化学吸附剂E．半化学吸附剂
参考答案：B
Were it not for the fact that I _____ very busy, I would go with you.[ ]
A. am
B. was
C. had been
D. were
垂柳可以吸收有害气体问这种有害气体是什么？
