It is likely that water is not ____ endless resource, nor ____ that can be made once more.
(2012江苏卷)— OK, I've had enough of it. I give up. —You can't your responsibilities.
I’m so glad you’ve come here to ________ this matter in person.
Walking alone in the dark, the boy whistled to ________ his courage.
Finally, my thanks go to my tutor, who has offered a lot of suggestions and comments on my paper and ________ every page of my draft.
(2012浙江卷) According to scientists, our mental abilities begin to______ from the age of 27 after reaching the highest level at 22.