The book was written in 1946, __________ the education system has witnessed great charges.
| A．when | B．during which | C．since then | D．since when |
______ at the news that his eyes rained tears.
| A．So was Tom sad | B．So sad was Tom |
| C．So sad Tom was | D．So Tom was sad |
—Has your former classmate come back from America?
—Yes, he _____ there for 8 years.
| A．has stayed | B．stays | C．stayed | D．had stayed |
—Hello, can I speak to Mr. Smith?
—I’m sorry, but it is 3 weeks _____ he worked here.
| A．before | B．since | C．after | D．while |
—It’s hard to believe that Jack should have fought with the policeman.
—Yes. If one ____ ask for trouble, it can’t be helped.
| A．may | B．need | C．must | D．should |
—When did your brother begin to show his interest in medicine.
—It was a Saturday _____ he noticed his classmate experimenting on a frog in the lab.
| A．that | B．what | C．when | D．which |