You'd better中的'd是什么意思?

You'd better中的'd是什么意思? You'd better do some reading.是什么意思? you'd better do something 中的d是不是had? You'd better 中的 'd 是什么的缩写 You'd better...中的“ 'd ”是什么? you'd better not .中的('d)是什么的缩写 You'd better know you'd better do YOU'D better 英语翻译you'd better ( ) ( ) ( ). you'd better get out while youcan.中的while you you'd better check yourself before wreck yourself是什么意思?