汉语说“鼠标左键”，说成英语是 left mouse button，而不是 mouse left button，因为 mouse button（鼠标按键）是一个语义整体，要表示“鼠标左键”或“鼠标右键”，应在其前加修饰语 left 和 right，即说成 left mouse button 和 right mouse button。比如：

The drag operation is still terminated by releasing the mouse button. 释放鼠标按键时，拖动操作将立即终止。

Click on the left mouse button. 单击鼠标左键。

click the left mouse button twice. 双击鼠标左键。

Click on the icon with the right mouse button. 用鼠标右键该图标。

If you are clicking in data, the left mouse button generally means selecting. 如果你在数据上单击, 则通常意味着选择。

Choose “printer” from the menu and click with the right muse button. 从菜单上选取“打印机”，然后点击鼠标右键。

Highlight the chosen area by clicking and holding down the left mouse button. 点击并摁住鼠标左键将所选区域高亮显示。