A team of nurses ________ the doctor in performing the operation on the boy wounded in the earthquake.

The newly published book , which refers ____ basic English grammar , is ____ only for beginners .

He had tried everything but it made little ____.

____cleaning the yard and making up the beds for the old, we also read newspapers for them and had chats with them.

—Please _________ the tigers. It’s dangerous to take photos with them.—Oh, I see. Thank you.