32-35DABC 36-40DCDBB
再问： 39为什么不是A啊
再答： 39.应该是D 主语从句， 抱歉没看清
再问： 但是主语从句的话,后面没有is啊
再答： (That the sun not the earth is trhe center of our plannetary system )was a difficult concept to grasp in the Middle Ages. 可以调整为 It was a a difficult concept to grasp in the Middle Ages that the sun not the earth is trhe center of our plannetary system. 以it作形式主语
