They laughing when they heard his funny voice.A. burst outB. fell aboutC. felt aboutD. bu

问题补充：

They laughing when they heard his funny voice.

A. burst out

B. fell about

C. felt about

D. burst into

答案：

(答案→)A. burst out

B. fell about

C. felt about

D. burst into

解析：考查词组：burst out laughing突然笑起来，句意是：当听到他滑稽的声音，他突然笑起来。选A。