他们正在开怀畅饮啤酒.用英语怎么说？

他们正在开怀畅饮啤酒.

They were regaling themselves with beer.

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。

regaling

VERB （以讲故事或笑话的方式）取悦；

例句
She was regaling us with tales of her youth.
她给我们讲她年轻时的事,逗着我们开心.

themselves

pron. 他[她，它]们自己，他们亲自，“himself”的复数，“herself”的复数；

例句
Most officers and men acquitted themselves well throughout the action.
大多数军官及士兵在整个战斗中表现出色。

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。

beer

n. 啤酒，麦酒，（一般）发酵饮料，[印，纺]比尔；

例句
On a table pushed against a wall there were bottles of beer and wine.
在一张靠墙的餐桌上有啤酒和葡萄酒。