A computer can perform many tasks at once.
电脑能同时做多项工作。
She fell in with my idea at once.
她立刻同意了我的主意。
We have several projects all on the boil at once.
我们热火朝天地同时上马了几个项目。
It is a physical impossibility to be in two places at once.
同时身处两地在自然法则上是不可能的。
He couldn't reasonably be expected to pay back the loan all at once.
公平合理地讲，不可能指望他一下子归还全部借款。
The award-winning novelist often has three or four books on the go at once.
那位获奖小说家经常是三四部小说同时写的。