--- I ____ so busily recently that I ____ no time to help you with your maths.
---That’s OK. I can manage it by myself.
| A．had been working; had had | B．have been working; had |
| C．have been working; have | D．am working; will have |
—Did you have any difficulty catching yesterday’s lecture?
—No. The professor spoke very clearly to make his speech easy _____.
| A．understood | B．understanding | C．to be understood | D．to understand |
After months of voyage, Columbus arrived in _____ later proved a new continent.
| A．where | B．which | C．what | D．that |
—Do you think our team will win the game?
—I don’t know. But this is the last chance. We _____ them to.
| A．hope | B．require | C．prefer | D．demand |
____ 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 |
_____ is known to us all is that the old scientist, for _____ life was hard in the past, still works very hard in his eighties.
| A．As; whom | B．What; whom | C．It; whose | D．As; whose |