New medicines and instruments ______ every day to extend life.
| A．develop | B．are being developed |
| C．are developing | D．have developed |
—Will you go fishing with me?
—___________．
| A．No, I'll be very busy | B．Yes, I'll be glad |
| C．Certainly, I'll be sorry | D．Certainly, I'll be glad to |
．You can't see the___________ now for they are having a meeting at the moment．
| A．editor-in-chiefs | B．by an hour |
| C．by hour | D．each hour |
He has a part - time job and was paid___________．
| A．by the hour | B．by an hour | C．by hour | D．each hour |
They gave us so warm a welcome that we were moved very much．It was a sight__________ we__________．
| A．what;have never forgotten | B．which; wre never forgotten |
| C．as ;will never forget | D．that; would never forget |
This coat will lose its color ___________ it's washed．
| A．as | B．after | C．until | D．while |