When the brawl happened,A. few people were at Sydney airport.B. a gang was ambushed by a rival gang.C. four suspects fled and others were arrested.D. 15 gang members were surrounded by 50 other gang members.

步骤 1：理解新闻内容
新闻首句提到dozensofpeopleatSydneyairport，而不是[A]项的few；[C]项与新闻内容相反，新闻说是4个人被捕，而不是4个人逃走；[D]项中的50othergangmembers与新闻最后一句witnessedbyabout50people不符。只有[B]项，agang被仇家伏击了，符合新闻内容。
步骤 2：分析选项
A. few people were at Sydney airport.
新闻首句提到dozensofpeopleatSydneyairport，而不是[A]项的few。
B. a gang was ambushed by a rival gang.
新闻内容提到gang被伏击，符合[B]项。
C. four suspects fled and others were arrested.
新闻内容提到4个人被捕，而不是4个人逃走，与[C]项相反。
D. 15 gang members were surrounded by 50 other gang members.
新闻最后一句提到witnessedbyabout50people，而不是[D]项中的50othergangmembers。