问题补充：
Seeing their son playing computer games all day, the parents don’t know it.
A. how to do
B. what to do
C. how to deal with
D. how to do with
答案：
A. how to do
B. what to do
(答案→)C. how to deal with
D. how to do with
解析：deal with与how连用；do with与what连用。句意：看见儿子整天玩电脑，父母不知道如何处理这件事。故选C。
