Many of    friends British people make at school remain    friends for life, so it is true that schooldays are “the best of life”.

A．the；不填

B．the; the

C．不填; the

D．不填；不填

隧道施工通风的主要目的是（）。

A.排除炮烟

B.降低温度

C.稀释施工车辆废气

D.降低粉尘浓度