1.once作副词,意为“一次”;“曾经,一度”;
We go to the factory once a day. 我们一天去工厂一次。
I once thought that the answer to this question was correct. 我一度认为这个问题的答案是正确的。
2. once作连词,意为“一旦……就”;(引导时间或条件从句)
Once it is gone, perhaps you will never get it back. 一旦失去什么,也许你再也找不回来。
3. 短语汇总
⑴all at once=all of a sudden突然,一下子;
⑵once in a while偶尔,有时;
【点题】
1.(2014山东)I don’t really like the author, _______ I have to admit his books are very exciting.
A. although B. unless C. until D. once
2.(2014天津)_______ you start eating in a healthier way, weight control will become much easier.
A. unless B. Although C. Before D. Once