The reason _______ he didn’t come was _______he was injured.
| A．that, because | B．why, that |
| C．why, because | D．that, that |
— Write to me when you get home.
— __________.
| A．I must | B．I should | C．I will | D．I can |
I was really anxious about you. You _______ home without a word.
| A．mustn’t leave | B．shouldn’t have left | C．couldn’t have left | D．needn’t leave |
“Did Jim come？” “I don’t know. He _______ while I was out.”
| A．might have come | B．might come |
| C．mush have come | D．should have come |
“Look at these tracks. It _______ be a wolf.” “Don’t be so sure. I think it _______ be a fox.”
| A．must; could | B．may; might |
| C．need; must | D．could; need |
“Show me your permit, please.” “Oh, it’s not in my pocket. It ______.”
| A．might fall out | B．could fall out |
| C．should have fallen out | D．must have fallen out |