The book was written in 1946, _______ the education system has witnessed great changes.
| A．when |
| B．during which |
| C．since then |
| D．since when |
The streets are all dry . It ____ during the night .
| A．can''t have rained | B．mustn''t have rained | C．couldn''t rain | D．shouldn''t have rained |
I ____ take a job . No one ____ stop me .
| A．will ; shall | B．will ; may | C．should ; will | D．shall ; may |
“When ____ he leave the hospital ? ”I asked the doctor .
| A．will | B．shall | C．can | D．may |
— They haven''t finished the work up to now .
— Well , he ____ .
| A．should have | B．should | C．ought to | D．ought have |
— ____ you please open the window ?
— Yes , I ____ .
| A．Would ; would | B．Would ; will | C．Will ; can | D．Must ; must |