A.text-muted B.text-success C.text-info D.text-warning
A.會(huì)有自動(dòng)的padding樣式 B.會(huì)有自動(dòng)的margin樣式 C.其字體默認(rèn)為14px D.其box-sizing默認(rèn)為border-box
A.center B.center-block C.horizontal-center D.vertical-center