三个必须做的外部名称空间声明是WSDL、SOAP和XSD (XML模式定义)。

The three external namespace declarations you have to make are WSDL, SOAP, and XSD (XML Schema Definition).

youdao

你必须完成三个书面作业。

You must complete three written assignments.

《牛津词典》

最糟糕的是必须在雨中等待三个小时。

The worst part was having to wait three hours in the rain.

《牛津词典》

For instance, if I wanted to change the sound that the cat is making, my God, now I have to change it on three places but like 30 places if all I've done is copy and paste.

举个例子，假如你想,改变猫的叫声，我的天啊，你现在必须改变三个地方,但是，我做了30多次复制和粘贴。

哈佛公开课 - 计算机科学课程节选

you always have to sit in the same room for three hours for multiple classes.

你必须在同一个房间为了多个课程坐三个小时。

对于古怪教授 - SpeakingMax英语口语达人

We have to decide three things: one, the name of the function.

我们必须决定三个事情：一，函数名。

哈佛公开课 - 计算机科学课程节选