Pollen and ash remains show that 2000 years ago the Mayans were growing maize with slash-and-burn agriculture in some areas that over the course of later centuries became permanently flooded wetlands.

从遗留的花粉和草木灰可看出距今2000年前生活在那里的玛雅人还在那里种植玉米，虽然种植方式还处在刀耕火种的原始方式，但那里毕竟还有土地。可是在随后的几百年里，这片土地已成了永久性的洪涝之地。

youdao

The cement fly ash is a base course material for pavement that has the advantage of both cement and fly ash stabilized granular.

水泥粉煤灰路面基层是一种兼有水泥和二灰稳定粒料优点的路面基层材料。

youdao

Of course we say grey series is not only refers to smoke gray, but includes red, yellow, blue, grey ash, ash.

当然我们说的灰色系列不是单指烟灰色，而是包括红灰、蓝灰、黄灰等在内的。

youdao

In winter of course healthy and sick ash trees are difficult to tell apart as the leaves will all have fallen to the ground.

BBC: The heartbreak of watching the slow death of ash trees

The drifting ash led to the closure of much of Europe's airspace over the course of the week.

BBC: Flying through volcanic ash clouds