问题补充：
Keep on trying, you will find a way out.
A. so
B. but
C. or
D. and
答案：
A. so
B. but
C. or
(答案→)D. and
解析：考查连词。本题是一个固定句式；祈使句+连词+陈述句；该句型=if引导的条件句+主句。本句Keep on trying，and you will find a way out=If you keep on trying, you will find a way out.如果该条件句使用否定式，那么原句就应该使用or。如：Hurry up, or we will be late.=If you don’t hurry up, you will be late.
