Without electronic computers ,much of today’s advanced technology .
| A.will not have been achieved | B.have not been achieved |
| C.would not have been achieved | D.had not been achieved |
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 |
I really don’t know _________ I put my wallet after I paid the bill.
| A.where was it | B.it was where that |
| C.where was it that | D.where it was that |
During the examination we are required to stay in our seats, keep our eyes on our work, ____ to anyone.
| A.instead of speaking | B.rather than speak |
| C.and not to speak | D.but would not speak |
________ these experiments were successfully completed would we think of going into humans.
| A.If only | B.Only if | C.So that | D.Even if |