With an appropriate modal verb:
(1)Peter____ come with us tonight, but he isn't very sure yet. (2)A computer____ think for itself; it must be told what to do.
【正确答案】：may;can't
【题目解析】：本题考查情态助动词。【要点透析】由第一句中的 not very sure可知,此处应填may,表示推测意义,即可能性。由第二句中的 must be可知,此处应填can't,表示不可能。
