问题
选择题
The toughest thing about success is _______ you have to keep on being a success.
A． that
B．when
C．what
D．why
答案
答案：A
考查宾表语从句的连接词。_______ you have to keep on being a success是表语从句，且从句句意完整，不缺成分，所以用that引导。 A。