Many scientists believe that global warming , if , will cause extreme climate changes this century .
| A．not stopping | B．no stop | C．not stopped | D．without stop ycy |
A poet and artist ________ coming to speak to us about Chinese poems and painting tomorrow.
| A．was | B．were | C．is | D．are |
It was after he got what he had wanted very much _______ he realized it was not important.
| A．when | B．that | C．since | D．as |
This year this factory has produced ________ cars as it did last year.
| A．as more than three times many | B．more than three times many as |
| C．more than three times as many | D．three times as more than many |
The famous writer our Chinese teacher often referred ________ at our school yesterday.
| A．to arrive | B．arrived | C．to arriving | D．to arrived |
Please go ________ the ship quickly. There is only ten minutes left.
| A．board | B．broad | C．aboard | D．abroad |