In many parts of the world, man has not realized the importance of the role of trees. He has cut them down in large numbers () that without them he has lost the best friends he had.

A. then found

B. only to find

C. but found

D. therefore found

造成重排岗位酸肟比失调的原因有（）。

A、配比设置不当

B、酸或肟调节阀、流量计卡死

C、温度三通调节阀卡

D、循环泵跳停