Hit the backspace key on a computer or typewriter keyboard.

敲计算机或打字机上的退格键。

youdao

An electric typewriter has an electric motor which takes some of the hard work out of typing for you by making the key pressure stronger.

电动打字机装有电机，增强了按键的力度，取代了人的某些繁重的按键工作。

youdao

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