当and 连接两个句子的时候,时态和结构应该怎么用比如说:He could go there and studies/study English.这里and后面的study Enligh,是could study Enligsh 的简化呢,还是应该写成 studies English?再比如说Cell phones can be used to take photos,to surf the Internet and to watch movies.后面的to surf the Internet 的to 和 to watch movies.的to 可以省略的吗?

He could go there and study English.
go there 和study English 这两个是并列的短语
不可以，被动语态后面的to不可以省略

The big clock which used to strike the hours day and night was damaged many years ago and has been silent ever since.教堂的钟很大，以前不分昼夜打点报时，但在很多年前遭到毁坏，从此便无声无息了。
The search proved difficult, for the puma was often observed at one place in the morning and at another place twenty miles away in the evening.这里的and就连接了两个并列成分，at one place in the morning和 at another place twenty miles away in the evening.所以and就是用来连接并列成分的。

时态保持一致

是表并列的，所以前后时态一致的，第一个应该是study ,第二个为被动语态，不可去掉

and连接的两个谓语部分一定要在时态和语态保持一直,前一个用study,后一个的to最好不要省略为了避免产生歧义,如果是由and并列的话一般可以省略!