Historical experience can as a most important source of information.
My friend's car alarm ________ at midnight because it was thundering.
—Let's just play a game or something else.—Sounds good, but give me a call before you come. My mom might try to ________ something else for me to do.
The thing that ________ is not whether you fail or not, but whether you try or not.
—There is still a copy of the book in the library. Will you go and borrow ____?—No, I’d rather buy ____ in the bookstore.
We must take measures to stop various kinds of pollution ______ the environment gets worse.