2.B

3.A

4.( 1) Get up early (work) and go to bed late (every day) without any laziness; See and hear, increase wisdom, and be full of physical strength.

(2) After leaving his post, Cheng Jun will do his best to educate the young people in his hometown. Wandering between mountains and rivers, walking briskly, eating meat with an open belly, full of energy and enjoying yourself.