People use a metal call box with a push-to-talk button to connect to a live operator, as Rose Shuman explains: "You just push a button, a big green button, and that will connect you directly to our operators who are sitting in front of computers, and speak your language.

VOA: special.2009.10.12

And in fact, as a sidebar, that is not syntactically correct, there's a simple button that you push that will check your syntax.

实际上，有个小道消息，你放入了，一个语义,结构。

麻省理工公开课 - 计算机科学及编程导论课程节选