拍照前确保相机是水平的。

Make sure the camera is ___level before you take the picture.

在我把它固定在墙上之前，你会说这个架子是水平的吗？

Before I fix it to the wall, would you say this shelf was ___level?

桌子需要是水平的，实验才能正常进行。

The table needs to be ___level for the experiment to work properly.