At last one of them took a piece of paper and began to draw a once翻译中文

问题描述:

At last one of them took a piece of paper and began to draw a once翻译中文

最后,他们中的一个拿出了一张纸并且开始画一个一次。

最后,其中一人拿起一张纸,立马开始画图.
句中 a once 可能是笔误,应该是 at once ,立刻之意.