Evidence obtained from observation and experiment is often used to ________ a scientific theory.
| A．confirm | B．claim |
| C．conclude | D．calculate |
—— I didn’t see her yesterday.
—— Oh, but you ＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿.
| A．must have | B．ought to | C．should have | D．cannot have |
She＿＿＿＿＿＿＿＿the film. She knows nothing about it.
| A．can’t see | B．can’t have seen | C．must see | D．mustn’t have seen |
—— Nacy＿＿＿＿＿＿＿＿＿ the letter from her mother.
—— No, she can’t have. The postman hasn’t come yet.
| A．can receive | B．can have received | C．must have received | D．must receive |
I don’t think he＿＿＿＿＿＿＿ a new bike.
| A．need to buy | B．needs buy | C．need | D．need buy |
Tom＿＿＿＿＿＿＿show his exam results to his parents.
| A．dare not | B．dared | C．dare to | D．dares not to |