—Lisa, what do you think of the job of being a nurse?—In my opinion, it ____ be difficult sometimes though it seems easy.
As we all know, water ______ hydrogen and oxygen.
When _____ help, one often says “Thank you.” or “it’s kind of you”
He narrowly escaped _______ by the falling tree.
_____ is known to us all, a skill can only be acquired through hard work.
There is no doubt _____ short sight is a serious problem among the youth of our country.