（现在分词短语作原因状语） 他们的店关门了，因为没有顾客。

They closed the door, there being no customers.

youdao

然而没多久，他发觉当了理发师后他并不忙碌，因为没有顾客上门。

But soon he found that as a barber, he was not busy because no guests came into his shop.

youdao

《打瞌睡的理发店老板》小镇的人口是有限的，理发店的老板也因为没有顾客而打起了瞌睡。

The boss of barber shop is sleeping the population is much small in this town, and the boss of barber shop is sleeping as few customers come.

youdao