他打算在大学学习生物，所以正在准备生物科目的A-level考试。

He wants to study biology at university, so he's preparing for his ___A-level in Biology.

她的英语水平已经达到了高级。

Her English has reached an advanced ___level.

他的英语水平达到了高级阶段。

His English has reached an advanced ___level.

用水平仪确保画框挂得笔直。

Use a ___level to make sure the picture frame hangs straight.