______environmental damage is done，it takes many years for the ecosystem to recover.
| A．Eyen if | B．If only | C．While | D．Once |
Twenty-four is an age fit to get married________.
| A．at | B．with | C．to | D．/ |
Rose was wild with joy ________the result of the examination.
| A．to | B．at | C．by | D．as |
I wonder if she______us,but I think if she______us we will be able to complete the task ahead of time.
| A．helps;helps | B．will help;has helped |
| C．helps;will help | D．will help;helps |
—I heard Charlotte had been drowned in the lake.
—Really！Her boat turned______,and ______she couldn’t swim.
| A．down;fortunately | B．up;unfortunate |
| C．over;unfortunately | D．down;unfortunately |
Despite his great efforts,he ______unsuccessfully after all.
| A．ended in | B．ended with | C．ended up | D．turned out |