当点击播放按钮，角色将在按下上箭头键时开始走动，释放按键时，返回空闲姿势。

When you hit the Play button, the character will start walking in place when you hold the up arrow key and return to the idle pose when you release it.

youdao

维持鼠标按键按下的状态下，用户可以操控箭头键将所选对象向上、下、左或右每次移动1个像素。

While holding down the mouse button, a user can manipulate the arrow keys to move the selection up, down, left, or right-one pixel at a time.

youdao

Now I'm hitting the down arrow.

先在我敲下箭头键。

哈佛公开课 - 计算机科学课程节选