后生可畏
the young deserve to be regarded with awe; a ragged colt may make a good horse; every oak has been an acorn
e.g. 小伙子进公司才三个月，已能独挡一面，真是后生可畏。
He entered the company only 3 months ago and is now working on his own. Here's a young man to be looked out for.
