但as也回用于固定搭配，像as we all know, as it is known, as is known to all, as it is, as is said above, as always mentioned above, as is usual, as is often the case, as is reported in the newspaper等。
eg. As we all know, Jack London is a famous American writer.
eg.These apple，which were bought by my father，are very sweet.
eg.She was very patient towards the children，which her husband seldom was.
eg.He said that he will love her forever，which was not true.