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第一空包含词组 have great trouble/difficult (in) doing sth做某事有困难.相信你理解它的感叹句式
What great trouble they have in doing sth!
第二孔考查名词后面三种非谓语动词作后置定语的含义.
the problem being discussed now(正在讨论的问题,动名词的被动与now/ at present连用)
the problem to be discussed tomorrow(明天要讨论的问题,不定式与将来时间连用)
the problem discussed yesterday(昨天讨论的问题,过去分词与过去时间连用)