Malaria is caused by a complex parasite that makes it hard to target with a vaccine.

VOA: standard.2010.01.20

We know now that it's caused by a related virus, called vaccinia, remember the virus that causes smallpox is called variola.

我们现在知道这病由一种相关的病毒引起,这种病毒叫牛痘病毒,想想天花病毒也被叫做牛痘病毒

耶鲁公开课 - 生物医学工程探索课程节选

The idea that emerged the memory of the '81-82 recession is very strong in our imagination because we think that it was caused by lax monetary policy by liberal thinking by the soft-hearted liberals who just didn't want to create any pain and suffering.

出现的观点,在我们的想象中,81-82年的经济衰退很严重,因为我们认为它是由于,松懈的货币政策，不拘一格的思想,那些仁慈的不想制造任何痛苦和疲劳的,自由主义者引发的。

耶鲁公开课 - 金融市场课程节选

"On the operations we are having at the moment, it is completely wrong to say that the loss of lives has been caused by the absence of helicopters,".

VOA: standard.2009.07.22

"We also have reports of civilian casualties, but the info we have from the Afghan National Army on the ground is that it is believed that that was caused by insurgent mortar fire,".

VOA: standard.2009.09.12

"The scene here at the bottom of the hill where hundreds of houses have been destroyed by a landslide caused by the earthquake, the scene is one of rescue, it's just pure rescue effort that seems devoid of emotion,".

VOA: standard.2009.09.03