题目内容：

there is enormous difficult （ ） planting trees in the desert.A in B on C with D to 这里各个选项详细解释下

优质解答

选A.difficulty 的惯用法有这么几种：difficulty in doing sth.如例句.difficulty of sth.如：You don't know the difficulty of the problem.sb.has difficulty with sth.如：I have a lot of difficulty with ques...