Usually a meteorological observatory (气象台) _____ air quality in urban areas from one to five: excellent, fairly good, slightly polluted, poor, and dangerous.

A．identifies

B．purifies

C．classifies

D．clarifies

盲目采用强力钻进技术参数，贪图进尺，会使钻孔弯曲率（）。

A、减小

B、增大

C、不变

D、无影响