5.16When we reached the station the train had not arrived yet; so we()

A. 　 century

B. 　 battles

C. 　 thing

D. 　 years

A. 　危害人体的电磁辐射

B. 　电磁辐射与环保

C. 　电磁辐射的热作用和非热作用

D. 　无处不在的电磁辐射

A. 　 when

B. 　 who

C. 　 why

D. 　 what

A. 　 as to be heard

B. 　 to be heard

C. 　 as to hear

D. 　 to hear

A. 　 me

B. 　 mine

C. 　 my

D. 　 myself

A. 　really

B. 　 almost

C. 　 hardly

D. 　 still

A. 　 that

B. 　 when

C. 　 who

D. 　 where

A. 　 need

B. 　 time

C. 　 aim

D. 　 peace