concentration on sth

• 专心； 集中精力

concentration on sth的用法和样例：

例句

1. She couldn't concentrate on a book very long.
   她不能长时间专心读一本书。
2. You must keep your mind on your work.
   你必须专心工作。
3. I can't concentrate on my work when I'm tired.
   我累了就无法集中精力工作。
4. You must focus on turning negatives into positives.
   你必须集中精力将消极的东西变成积极的东西。