The mother tears at the sight of her long lost son, who was sent back by two policemen .
A. burst into
B. burst out
C. burst away
D. burst up
网友回答
A. burst into
(答案→)B. burst out
C. burst away
D. burst up
解析：试题分析：句意为：当观众朋友们听到这个滑稽的故事时，他们突然发出了阵阵笑声
A.闯出来；突发；摆脱 B闯入；情绪的突然发作 C爆发，发生 D闯入
固定短语：burst into laughter突然笑出来
故B正确