______ the moment ________ different schools of the world students are having different classes.
A. In; at B At; in C In ; in D.At; at
—Look at the flowers I gave you last month. They are dying! ________ do you water them?
—Sorry, I forgot to water them.
| A．How long | B．How often |
| C．How soon | D．How much |
—When will you return the book to me?
—I’ll give it to you _________ I finish it.
| A．once | B．until |
| C．as soon as | D．unless |
“Learning from Lei Feng Day” is only two weeks from now. We need to ________ a plan about it.
| A．come up with | B．put up |
| C．call up | D．set up |
—Look, someone left a book.
—Oh, yeah … This book ________be Kitty’s. Only she likes to read this kind of books.
| A．can | B．must |
| C．may | D．might |
Look, so many people are running out of the station. I wonder what ________.
| A．is happened | B．was happening |
| C．is happening | D．had happened |