________they decide which college to go to，students should research the admission procedures.
| A．As | B．While | C．Until | D．Once |
The research showed beyond ________ that smoking contributes to heart diseases.
| A．wonder | B．doubt | C．problem | D．use |
______ the police thought he was the most likely one, since they had no exact proof about it, they could not arrest him.
| A．Although | B．As long as | C．If only | D．As soon as |
Either you or one of your students ______ to attend the meeting that is due tomorrow.
| A．are | B．is | C．have | D．be |
Please do me a favor — ______ my friend Mr. Smith to Youth Theater at 7:30 tonight.
| A．to invite | B．inviting | C．invite | D．invited |
You and I could hardly work together,?
| A． | could you | B． | couldn't I | C． | couldn't we | D． | could we |