是一本教材,绝对干净,没写字。要30.' v8 e9 H5 U0 y' N' Z f
- J; a2 e# Q- V+ y$ }2 T4 c
% }- Y6 E% R' E& bOperation of wastewater treatment Plant, " T7 f1 K. d, t4 }, e : n3 P- }* u) i1 ]4 M0 `6 vA field study training program, 6 H* x* I' w6 {2 ]4 @% M0 T. U, I* n3 J8 g+ `5 m
Volume 1 , Seventh Edition