单项选择题
A.2 B.5 C.10 D.15
A.55% B.65% C.75% D.85%
A.检测开始前3天应为晴天或少云天气; B.检测日应为晴天或少云大气 C.检测期间室外温度波动应比较小 D.检测日工作高度处的室外风速不应超过5m/s