_______cloning human embryos is not legal in many countries, some scientists are already pushing ahead with research in order to produce a cloned human baby.
The manager suggested an earlier date ____________ the meeting.
Some pre-school children go to a day care center, __________ they learn simple games and songs.
---Have you heard the latest news?
---No, What?
_____ in the queue for half an hour,Tom suddenly realized that he had left his wallet at home.
The library needs _____,but it’ll have to wait until Friday.