Premature birth is the main cause of perinatal mortality.

早产是围产期死亡的主要原因。

《柯林斯英汉双解大词典》

If instead we regard the financing of warfare by taxation in this period as a background condition, then we will see the English reverse themselves as the main cause of the revolt.

如果我们将这一时期的通过税收来支持军事作为背景条件，那么我们就会看到英国人自己的失败反倒是造成反抗的主要原因。

youdao

It is believed that greenhouse gases are the main cause of global warming.

人们相信温室气体是全球变暖的主因。

youdao

The two researchers closely studied the records that listed errors involving medicines as the main cause of death.

VOA: special.2010.07.13

The Agriculture Department says poverty is the main cause of food insecurity and hunger in the United States.

VOA: special.2009.11.23

But Ban Ki-Moon said Tuesday that the evidence is "quite clear" that humans are the main cause of temperatures rising faster than expected.

VOA: special.2009.12.12

But a preliminary investigation indicates that typhoon-force winds, not pilot error, was the main cause.

CNN: How to Repair a Carrier

But the examination was unable to establish whether measles was the main cause of his death.

BBC: Gareth Williams

"The main cause of food insecurity in Africa is war and conflict, " Ms Rudd said.

BBC: Minister calls for more Horn of Africa aid