New ideas have been put into practice ______ he was elected our leader.
A. for
B. after
C. since
D. hence
Miranda lost weight ______ being on a diet.
A. by
B. with
C. to
D. from
条件致病菌的感染是
A. 外源性感染为主
B. 原为正常菌群,特定条件而感染
C. 与细菌寄生部位无关
D. 与机体免疫力无关
E. 易感人群为婴幼儿
I will get an exam tomorrow, so for ________ reasons I won't go out tonight.
A. direct
B. plain
C. unknown
D. obscure