请问,这题应该选择什么.怎么理解
问题描述：
请问,这题应该选择什么.怎么理解
Tom has much difficulty _____ Chinese so he often asks me _____ help
A.to understand; with B.understanding; of
C.to understand; for D.understanding; for
答
D
have difficulty doing sth是固定搭配
ask sb for help也是固定搭配
汤姆在理解中文方面有困难,所以他经常向我寻求帮助.