Question

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

Answer 1

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

Answer 2

选A or在这里表示否则