单选题 The author's main purpose in writing this passage is most probably to______.

A、 complain about people's slow actions to protect the environment
B、 advise people to take actions to protect the environment
C、 show himself to be an active environment protector
D、 point out the bad effects of technology in protecting environment

【正确答案】 B

【答案解析】[解析] 推理判断题。根据文章中最后一句But when more and more people become aware of the importance and take it as their personal responsibilities，the condition of the air will be improved得知，当越来越多的人意识到它的重要性并把它当作自己的责任时，空气状况就会好转。可以判断出答案为[B]。