第一题选B 这个句子的主语是the tree 谓语是have been moved,blown down 是过去分词作定语修饰the tree,因为tree做不出blow这个动作,所以用过去分词.
第二题选D,主语是they,谓语是use,to keep the traffic running smoothly是动词不定式作宾语.这道题选择D的原因是 keep sth doing
第三题选A 主语是he,谓语是drink,宾语是juice,from fresh fruit grown on his own farm修饰juice是定语,其中的grown on his own farm 修饰fresh fruit