这两句英语有语法错误么

第一句,book是不能do任何事的,所以应该是how does the book help people to.干吗干吗,或者in what way does the book help people to.(比如 to become more optimistic about life,或者之类的）.
第二句,可以做句子的一部分,比如 this is why we say the internet is useful but dangerous.如果自己成一个问句要改成 why do we say the internet is useful but dangerous.