1.In the Internet cafe,the computers are (connected ) to the Internet,
被动语态；被链接到……
2.He watched many (videos ) for lerning English.
many 后接名词复数.
3.If you want to be a good speaker,you should practice (speaking ) every day.
practice doing sth 固定用法‘ 练习做某事
加油!不明白再问!