复数： rainfalls

Amazonian soya farmers need it to guarantee them decent rainfall .

亚马逊种植大豆的农民需要森林保证足够的降雨。

Changes in rainfall will require new agricultural techniques .

降雨量的变化将要求我们拥有新的农业技术。

Rainfall has increased in some areas in recent days .

不过最近在一些地方，降水量有所增加。

Regions with heavy rainfall may not either .

雨量充沛的地区也不需要。

But rainfall was usually abundant , and harvests adequate .

但是，雨水通常非常充沛，所以丰收还是有保障的。