法官在桌子上敲下他的木槌。

The judge brought his hammer down on the table.

《牛津词典》

他用锤子正对着钉子敲下去。

He hit the nail squarely on the head with the hammer.

《牛津词典》

不久前，他试图把成熟的芒果从树上敲下来，弄伤了肩膀。

He hurt his shoulder not long ago, trying to knock ripe mangoes from a tree.

youdao

So in a moment you're going to go ahead and hit the spacebar and then as things fall from the screen when they line up with the left arrow, hit the left arrow with a different arrow, hit that arrow and see how good a score you can get.

一会儿你走到前面，敲一下空格键,当屏幕上面的东西从左边往下掉的时候,你就敲一下键盘上的左键,是哪个方向，敲对应的方向键就可以了,我们来看看你能得多少分。

哈佛公开课 - 计算机科学课程节选

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

So if you've ever seen or used an old school typewriter, you might recall that when you're typing something out on an old mechanical typewriter, - when you like hit the char-- when you hit the enter key to move the head back to the left hand side to the next line or you would pull down some lever, it was really a two part process.

如果你们有谁曾经看过或用过老式打字机，可能还记得，当你在,这种老式打字机上打字的时候，当你-,敲入回车键，跳转到,下一行的最左边，或者,拉一下杆，这个需要两步走。

哈佛公开课 - 计算机科学课程节选