My collar won't button down.

我的领子扣不起来。

It is the second button down.

这是在倒数第二行。

Button down his shirt If you roll up your sleeves, bigger can be better.

穿带有衣领扣的男式衬衫如果你要卷起袖子，卷得大一点比较好。

This a document source, which is about how to get key board button down msg.

这是一个文本资源，主要是关于如何从键盘获取按键消息的。

We click this button down here, and when it's ready, the green play button will become active.

当一切就绪，点底下的按钮，绿色的键，激活程序。