倍半萜类化合物中异戊二烯单元的数目是()
A.2个
B.3个
C.4个
D.5个
E.6个
参考答案:B
26. The professor was asked to write an article for the newspaper, ___________about the left-behind children in the countryside.
A.any
B.one
C.that
D.It
癫痫发作时应迅速喂入抗癫痫药物。