To their surprise, they found the lecture given by the famous professor easy ______.
| A．to be understood | B．to understand | C．understanding | D．understood |
Remember ______ the book when you have finished it.
| A．putting back | B．having put back | C．to put back | D．to have put back |
I need one more stamp before my collection______.
| A．is completed | B．completes | C．has been completed | D．has completed |
Is there a shop around ______ I can get some stamps and envelops?
| A．which | B．where | C．that | D．how |
—Li Ming went abroad in 2000.
—No wonder. I ______ him ever since.
| A．don’t see | B．hadn’t seen | C．didn’t see | D．haven’t seen |
It won’t be quite a long time ________ your son is back, so don’t be worried.
| A．that | B．since | C．before | D．until |