为什么选C,我错了还是答案错了?Tom's mother is busy _____ breakfast for Tom

为什么选C,我错了还是答案错了?Tom's mother is busy _____ breakfast for Tom Tom's family name is tom中哪里错了 be busy with与be busy doing如何替换 Tom's mother is busy cooking Tom's mother is worried _____ her son's eyesight. Tom's mother is _____(thin) than Mary's Tom's mother _____ a blue sweater for Tom's grandpa.A.wears He is buys a present for Tom 哪里错了 tom is _____(busy) today than yesterday. Tom is much _____(busy)than Sam i think is tom's这句话怎么错了 allen is tom's ( ) A,cousin B,mother C,aunt 为什么选c?还是我答案错了?..