Mike said that he wanted to ______ in a foreign country one day.[ ]

A. go to sightseeing                  

B. go to sightsee

C. go sightseeing                      

D. go sightsee

延胡索中具有镇静催眠作用的成分是（）

A.延胡索甲素

B.去氢延胡索甲素

C.延胡索丑素

D.延胡索丙素

E.左旋四氢巴马汀