选A,解释如下：seem常用于it作形式主语的“It seems/seemed that……”结构,如：
a) It seems that you were lying.
b) It seemed that he had been a scientist.
c) It seems impossible that he will be here tomorrow.
[注]1）在这一句式中,常省去that,如例a可改为：It seems you were lying.
2)间或在seem后可跟一形容词,如例c. 更多seem用法可参照 http://zhidao.baidu.com/question/149156283.html希望上述能帮助你!