【题目】People are advised not to smoke at home, since passive smoking is ________ to people around them. Which is Not proper for the blank?
A. dangerous B. protective
C. hazardous D. risky
在线课程【答案】B
【解析】
试题分析：句意：被动吸烟对周围的人是不好的。A. dangerous危险的B. protective有保护的；C. hazardous有危险的；D. risky冒险的。A、C、D都符合题意，故选B。