bootstrap row 中，如何使得所有 col 的高度和一行中最高 col 一样

/*
enhance bootstrap 3
Note that flexbox isn't supported in IE<10.

refer to: 
  https://stackoverflow.com/a/23305885
  http://acmetech.github.io/todc-bootstrap-3/examples/equal-height-columns/

*/

.row-eq-height {
  display: -webkit-box;
  display: -webkit-flex;
  display: -ms-flexbox;
  display: flex;
}