塑料管道与地下高压石油、天然气管平行净距为（）m？
A、5m
B、8m
C、10m
D、15m
参考答案：C
-What __________ you __________ at 6：00 yesterday evening?
-I was watching TV with my parents.
A. did, do
B. were, doing
C. are, doing
D did doing
