There are so many tall trees in the forest,______________.
| A．some of them measures over 50 meters | B．some of which measuring over 50 meters |
| C．some of them measuring over 50 meters | D．some of which measures over 50 meters |
I failed in the final examination last term and only then _______ the importance of studies.
| A．I realized | B．I had realized |
| C．had I realized | D．did I realize |
Only by practising a few hours every day _______ be able to master the language.
| A．you can | B．will you |
| C．you will | D．can you |
_______ the people have become masters of their country _______ science can really serve the people.
| A．It is only then; that |
| B．It was that; when |
| C．It is only when; that |
| D．It was when; then |
—I would never come to this restaurant again.The food is terrible!
—_______.
| A．Nor am I | B．Neither would I |
| C．Same with me | D．So do I |
The old couple have married for 40 years and never once _______ with each other.
| A．they had quarreled |
| B．they have quarreled |
| C．have they quarreled |
| D．had they quarreled |