问题补充：
Sometimes the parents have a difficult time their children.
A. communicate with
B. getting on with
C. to grow up
D. looking through
答案：
A. communicate with
(答案→)B. getting on with
C. to grow up
D. looking through
解析：首先，have a difficult time (in) doing sth.为固定搭配，表示做某事时有困难，类似的结构还有have trouble (in) doing sth.，由此排除A、C选项；随后get on with表“相处”，look through表示“看穿”，含义上B选项更符合句意，由此可知答案为B
