When the land was used up or the river was dirty in one place, man moved to another place.

当一个地方的土地用完或河流变脏了，人们就搬到另一个地方。

youdao

Some factories are pouring dirty water into the river.

有一些工厂正把污水注入小河。

youdao

A bullock cart is crossing the river now, so the water is dirty and it can't be drunk.

一辆牛车正在过河，所以河水很脏，不能喝。

youdao

The water from the Mississippi River was too dirty.

VOA: special.2010.03.28

Yet unless the remitters became embroiled in a serious crime, often involving drug money, Western lawmakers largely ignored them, focusing instead on trying to dam the river of dirty money that flowed through traditional banking channels--chiefly through the 1970 Bank Secrecy Act, and later its amendments, which required banks to file reports of suspicious activity and high-dollar transactions, and to maintain information about account holders' identities.

FORBES: On The Cover/Top Stories

The boys made collages depicting their journeys through the desert: the snakes, the coyotes, the dirty river, the truck, and the train commonly referred to as "La Bestia" (The Beast) because of its many dangers.

CNN: Don't turn your back on these children

Those glorious inundations moved massive quantities of sediment through the Grand Canyon, wiping the slate dirty, and making a muddy mess of silt and muck that would make modern river rafters cringe.

ECONOMIST: Flooding the Grand Canyon