从供选择的答案中选出应填入下列英文语句中______内的正确答案。 Toolboxes and menus in many application

从供选择的答案中选出应填入下列英文语句中______内的正确答案。

Toolboxes and menus in many application programs were(1)for working with the mouse. The mouse controls a pointer on the screen. You move the pointer by(2)the mouse over aflat surface in the direction you want the pointer to move. If you run out of(3)to move the mouse, lift it up and put it down again. The pointer moves only when the mouse is(4)the flat surface. Moving the mouse pointer across the screen does not affect the document, the pointer simply(5)a location on the screen. When you press the mouse button, something happens at the location of the pointer.