____ our natural resources is very necessary.
| A．The most we make of | B．The most we make |
| C．The most which we make | D．Most which we make of |
She ____ to her hometown several times.
| A．has been | B．has gone | C．went | D．is going |
It _____ Jane and Mary who helped me the other day.
| A．is | B．was | C．are | D．were |
I _____ to bed when the telephone rang.
| A．have been | B．went | C．am going | D．was going |
Jane _____ some washing this time yesterday.
| A．is doing | B．had done | C．was doing | D．did |
When I got to the school, the first class _____.
| A．had begun | B．began | C．is beginning | D．has begun |