题目

— Who's that boy reading in the garden? Is it David?— It _________ be David. I saw him in the classroom just now.A.must B.can't C.may 答案：【答案】B【解析】句意：——那个在花园里读书的男孩是谁?这是大卫吗?——不可能是大卫。我刚才看见他在教室里。考查情态动词。must必须；can't不可能；may可以；根据“I saw him in the classroom just now.”可知我刚才看见他在教室里，可推测出此处是“不可能”，故选B。9.   Worries and problems are _________ (正常的)in life.