Have your breakfast at once ,_________ you will be late for class .A.or B.so C.and D.but

A
这是个常见的句型：
祈使句（动词原形开头,表条件） + or + 陈述句（一般用will + 动词原形）
表否定,中间用or
Hurry up,or you 'll miss the train.
=If you don't hurry,you'll miss the train Work hard ,and you'll catch up with him.
如果表肯定
用
祈使句（动词原形开头,表条件） + and + 陈述句（一般用will + 动词原形）
Work hard,and you'll catch up with him.
=If you work hard,you'll catch up with him