And now, if I'm touching mouse pointer, we saw that Boolean expression before, play sound meow, wait a couple of seconds, and then just keep checking.

现在，如果我们碰下鼠标指针，起初我们看到一个布尔表达式，播放猫叫的声音，等几秒钟，然后如刚才那样做检测。

哈佛公开课 - 计算机科学课程节选

And this puzzle piece here colored in blue because it's a Boolean expression is just something that--whose answer is either a yes or no, 0 true or false, one or zero.

这个拼图染成蓝色,因为它是布尔表达式,它的结果只可能是肯定或否定，对或错，1或者。

哈佛公开课 - 计算机科学课程节选

Scratch This Boolean expression allows you to say to scratch if you are touching the mouse pointer, the little arrow, do something. How do we do something?

布尔表达式允许你告诉,当你触碰到鼠标指针，也就是小箭头，程序就相应地做一些事情？

哈佛公开课 - 计算机科学课程节选

Turns out with a Boolean expression, you don't have use the equality operator equals equals, you can just say what you mean.

结果用一个bool表达式，你不需要使用等号操作符“==“了，你只要说出你的意思。

哈佛公开课 - 计算机科学课程节选

That's what's called a Boolean expression named after literally a man named Boole.

这就是以Boolean这个人,的名字命名的布尔表达式。

哈佛公开课 - 计算机科学课程节选

Scratch The syntax actually looks reminiscent to Scratch, where you have a puzzle piece reminiscent of this shape, but you have to say "if" followed by a space, followed by in parenthesis, the Boolean expression that you want to check -- more on those in a moment.

这个语法看起来使人想起，那里有一个这种形状的程序块，但是你必须说明“if“后面跟着一个空格，跟着一个括号，一个你需要核对的布尔表达式,-还有更多的。

哈佛公开课 - 计算机科学课程节选