请问我这个句子的语法对吗?

题目

请问我这个句子的语法对吗?
First and foremost, no one could deny that the Internet, which was created by the rapidly developed science and technology, is the most convenient way to communicate among people. Since the Internet was invented, we can send e-mails to our friends within some seconds. We could keep in touch with our families wherever we are. Before the Internet was came, it is hardly communicate with my mother when I went abroad to study.
谢谢各位!
那请问before到底能用在哪里呢？句首应该如何用呢？
抱歉又多问了个问题。。。

答案

1.no one can deny ,不是could,因为你陈述的是客观事实,只能用一般现在时态.同理：we can keep in touch,不是we could keep in touch with.2.Since 这句,最好写为,Thanks to the invention of the Internet,we can s...