问题补充：
----It’s traditional in China to firecrackers on Spring Festival.
----But the serious smog（雾霾）nowadays needs us to stop it.
A. give out
B. set off
C. put off
D. show off
答案：
A. give out
B. set off
C. put off
D. show off
解析：句意：春节放鞭炮是中国传统。但现在严重的雾霾需要我们阻止它。give out分发，赠送； set off出发; （使）开始; 引起; 点燃; put off推迟；show off使突出; 炫耀，卖弄。所以选B。
