They were all shrieking with laughter.是什么意思？

They were all shrieking with laughter.

他们都发出了尖锐的笑声.

they

pron. 他/她/它们，人们，大家，政府，当局，她们；

例句
The storms had abated by the time they rounded Cape Horn.
他们绕过合恩角时，暴风雨已经减弱。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

all

adj. 全部的，一切的，各种的，极度的，尽量的；pron. 全部，一切，每个人，每件东西，全部情况；adv. 全部地，完全地，每个，非常；n. 全体，[常作A-]整体，[常与my, your, his, her等连用]（某人）所有的一切；

例句
Many parents simply abdicate all responsibility for their children.
许多父母对孩子简直是完全撒手不管。

shrieking

v. 尖叫( shriek的现在分词 )；

例句
Still the horrible shrieking came out of his mouth.
他的嘴里还是发出了恐怖的尖叫声。

with

prep. 和，跟，随着，关于，和…一致；

例句
A waiter entered with a tray...
侍者端着托盘进来了。

laughter

n. 笑，笑声，〈古〉好笑的事，〈美俚〉力量悬殊得可笑的体育比赛，大笑；

例句
Children were changing classrooms amid laughter and shouts.
孩子们在欢笑声和喊叫声中换教室。