Question

—Is the letter from your mother?
—Yes. But she ________ the letter herself, because she doesn't even know one word.

A．needn't have written	B．can't have written
C．might not have written	D．should not have written

Answer 1

B

選B　考查情態(tài)動詞。句意：“這封信是你母親來的吧？”“是的。但這封信不可能是她自己寫的，因為她一個字也不認(rèn)識�！备鶕�(jù)because引導(dǎo)的原因狀語從句可知，此處應(yīng)用can't have done表示對過去發(fā)生的事很有把握的否定推測。