Only when___________ according to the directions can the medicine be quite effective.
A. taking B. taken C. being taken D. having been taken
To be successful, you need to remember that ___________you might be very busy, you need to be energetic and enthusiastic.
A. as though B. in case C. even if D. now that
Not until all the fish died in the lake __________ how serious the pollution was.
A. did the villagers realize B. the villagers realized
C. realized the villagers D. do the villagers realize
A student at a Nevada middle school opened fire on campus, wounding two l2-year-old boys and__________ a math teacher.
A. kill B. killing C. killed D. to kill
It never will rain roses. __________ we want to have more roses. we must plant trees.
A. When B. Unless C. Until D. While
Peter has gone to Beijing, but I’m wondering why he ________ in such a hurry.
A. left B. has left C. leaves D. was leaving
