He threw away his cup and became even happier. Which of the following is correct for the underlined word in the sentence?
Most people have realized the ______ of protecting the environment.
Peter is honest boy and______ good friend of mine.
I bought a new book in the bookstore. My mother asked me.
—Do you know that Jeremy Lin ______ to give us a talk next week'?—Really? That's good news.
—What do you think of the film named Iron Man 3?—I have no idea, because I ______ it yet.