It is not known what causes the disease.

这种病的起因不明。

《牛津词典》

So what causes mass strandings?

那么是什么导致了大规模的搁浅呢？

youdao

What causes fashions to change?

是什么导致了时尚的变化？

youdao

There is some debate about exactly what causes the brain to release endorphins.

VOA: special.2010.06.08

The Washington Post surveyed its readership and discovered that ask people what they thought was the most significant causes of the shooting.

华盛顿邮报》在读者中进行了调查,并且发现当询问人们,他们认为,枪杀案发生的主要原因是什么。

麻省理工公开课 - 媒体、教育、市场课程节选

The contract has to specify what are the causes of, let's say, death or a situation in which one is covered.

合约中必须指明,合约建立目的，比如说，死亡或者承保的是什么情况。

耶鲁公开课 - 金融市场课程节选

However, the recent purchase by some of the most respected and largest U.S. financial institutions causes one to wonder what information led to their decisions.

FORBES: J.C.Penney: Limited Stock Float Adds to the Wild Ride

As always, bad government policy, not finite resources or growth, is what causes shortages.

FORBES: Sell Your Commodities!

There are a lot of theories -- nobody really knows what causes it.

CNN: Smoking quadruples risk for vision-stealing eye disease