He isn't in the school .I think he __be ill.A.can B.must为什么?_英语解答

He isn't in the school .I think he __be ill.
A.can B.must为什么?

人气：449 ℃　时间：2020-01-30 18:08:43

解答

must be 表肯定推测“可能是...”
can't be 表否定推测“不可能是...”
这时就不能用mustn't be
若用can则表示为“能够”等意