淫羊藿的药用部位是 。
A. 全草
B. 叶
C. 根
D. 根茎
当归挥发油中主要含有 。
A. 蒎烯
B. 藁本内酯、正丁烯基酰内酯
C. 柠檬烯
D. 阿魏酸
Bob hasn’t finished the report yet, but he promised _____ it ready tomorrow afternoon.
A. to have
B. have had
C. having
D. has
I still remember _____ to the man who we later knew was the sales manager of the company.
A. to be introduced
B. being introduced
C. having introduced
D. to have introduced