问题
选择题
The problem with being a time waster is _____the online game playing often spills over into the periods of time that should be productive.
A．what
B．which
C．that
D．whether
答案
答案：C
本题考查名词性从句。句中that引导表语从句，在从句中不作任何成分，但在表语从句中不可以省略，故选C。