问题
选择题
This problem may lead to more serious ones if ____ unsolved.
A．making
B．remained
C．keeping
D．left
答案
答案：D
本题考查省略句的用法。此处完整的句子应为：This problem may lead to more serious ones if it is left unsolved.在从句中如果主语与主句的主语一致时，常将从句的主语和谓语的一部分省略。