________our earth，or else it will be no longer fit for us to live on.
| A．Protecte | B．To protect | C．Protecting | D．Protect |
“The Mozart effect” is a study described in 1993 in Nature _______ aroused public interest about the idea _______ listening to a classical music somehow improves the brain.
| A．that; which | B．what; why |
| C．who; that | D．which; that |
Based on the agreement, all payments _____ be made by the end of the month.
| A．shall | B．may | C．can | D．will |
—Do you know the headmaster well?
—Not really, just a nodding ______.
| A．acquaintance | B．Administration |
| C．consequence | D．consideration |
---I wonder what makes you a good salesperson.
---I _______ as a waiter for three years, which contributes a lot to my today’s work.
A. serve B. have served
C served D. had served
A lot of the waste thrown away in the U.S. ______ being shipped overseas to China, India, and other developing countries.
| A．breaks up | B．clears up |
| C．sums up | D．ends up |