Having a trip abroad is certainly good for the old couple, but it remains _______whether they will enjoy it.
| A．to see |
| B．to be seen |
| C．seeing |
| D．seen |
______ 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 |
You and I could hardly work together, _____ ?
| A．could you | B．couldn’t I | C．couldn’t we | D．could we |
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 |
— It’s the office! So you ______know eating is not allowed here.
— Oh, sorry.
| A．must | B．will | C．may | D．need |