关于and 的并列问题,一直都是我很头疼的

题目

关于and 的并列问题,一直都是我很头疼的
给几个例句,大家看看是怎么用
（1）表示他应该做A、B两件事的时候,
是He should do A and do B .还是He should do A and should do B.
(2)表示做A、B两事很重要时,
是It's important for us to do A and do B还是It's important for us to do A and to do B.
(3)A事件表示can do sth ,而B事件就是 be done
比如是He can sing and be praised quite often.还是He can sing and is praised quite often.
这都是令我很头疼的东西,希望大家最好能在帮我归纳一点关于怎样判断and并列结构的问题,这对单选和作文都很重要.

答案

前两个都选第一个,同性质的并列（如：两名词、两件事）可以看做一个整体,
I like (apples and bananas ).
He should (do homework and wash his clothes ).
It's important to (study and do excise ).
第三句选第二个,两件事的时态不同,可以看作两个独立的句子,而后句省略主语
He can sing and is (he )praised quite often.