---Why do you keep the windows open on such a cold day? ---There are so many students here, so we want to keep the air nice and __.
There are _______ new words in the article, so it’s not difficult for us.
He _______the book in half a year
-I usually go there by train. -Why not ________by boat for a change?
I saw two _______ ________ an apple when I came by.
The sports report is really boring. I can’t _______ it.