“A lot of skills are needed for the job. You have to make sure you don’t turn two pages at once and make sure you find the repeats in the music when you have to go back to the right spot.” Mr Titterton explained.

你认为这里的 at once 翻译不通，可能是因为你把 at once 理解错了。

比如在这里你把它理解成“立即”“马上”，句子意思就不通了。其实这里的 at once 是表示“同时”“一次”。You have to make sure you don’t turn two pages at once… 的意思是：你必须确保你不会一次翻两页……

附 at once 的几个常见用法：

1. 表示“立即”“马上”。如：

I recognized him at once. 我立刻就认出了他。

He realized his mistake at once. 他马上认识到自己的错误。

2. 表示“同时”：

Don’t all speak at once, one at a time! 不要同时说，一次一个!

A computer can perform many tasks at once. 电脑能同时做多项工作。

3. 表示“一次”：

I can only do one thing at once. 我一次只能做一件事。

Don't spend the money all at once. 不要把钱一次就花光。

4. 用于at once…and…，与both…and…同义。如：

He was at once happy and sad. 他悲喜交集。

The story is at once amusing and instructive. 这个故事既有趣，又有益。