他们睡觉时窒息而死。用英语怎么说？

他们睡觉时窒息而死。

They were suffocated as they slept.

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。

suffocated

v. （使某人）窒息而死( suffocate的过去式和过去分词 )，（将某人）闷死，让人感觉闷热，憋气；

例句
They were suffocated as they slept.
他们睡觉时窒息而死。

as

adv. 同样地，一样地，例如；prep. 作为，以…的身份，如

例句
As far as I can recall, Patti was a Smith.
我记得帕蒂是姓史密斯的。

slept

v. 睡觉（ sleep的过去式和过去分词 ）；

例句
I hardly slept at all and felt pretty awful...
我基本上没睡，觉得很难受。