请在你完成的每个项目旁打勾。

Please put a ___check by each item you have completed.

她在正确答案旁边打了个勾。

She made a ___check next to the correct answer.

我的老师在我的试卷上打了个勾，表示它是正确的。

My teacher put a ___check on my paper to show it was correct.