__________ you understand the rule, you will have no further difficulty.
| A．While | B．Once | C．Though | D．Unless |
I wrote a letter of complaint(投诉)，and the airline have promised to _______the matter．
| A．1ook at． | B．1ook into | C．1ook after | D．1ook out |
I’m happy that you agreed to work with us again．and I look forward to______you next week．
| A．being seen | B．see | C．seeing | D．having seen |
-- Could I use your computer for a few moments, please?
--- ________. I’m not using it myself.
| A．Come on | B．It depends | C．Go ahead | D．That’s great |
People have always been curious _________ how living things on the earth began.
| A．in | B．at | C．of | D．about |
I really don’t think my best friend will be angry, but I’11 go and see her，in case she _______.
| A．will be | B．is | C．does | D．has been |