The research is so designed that once _______ nothing can be done to change it.
| A．begins | B．having begun |
| C．beginning | D．begun |
Customers are asked to make sure that theythe right change before leaving the shop.
| A．will give | B．have been given |
| C．have given | D．will be given |
He is looking for a job, onehe can make the most of his talent.
| A．of which | B．which |
| C．where | D．That |
The manager was so satisfied with allI had doneshe gave me a promotion.
| A．that; that | B．what; that |
| C．what; as | D．that; which |
—Do you mind my opening the window? It’s a bit hot in here.
— , as a matter of fact.
| A．Go ahead | B．Not at all |
| C．Yes, I do | D．No problem |
I visited Jiuzhaigou Valley, I was deeply impressed with its beautiful scenery.
| A．At the first time | B．First time when |
| C．For the first time | D．The first time |