Severe winter weather, heavy rains and landslides are believed to have destroyed much of the butterfly population.

VOA: special.2010.04.27

I think they're very heavy, indeed, but I don't know how much they weigh.

他们负重确实很多,但是我不知道他们的负重是多少

耶鲁公开课 - 古希腊历史简介课程节选

I think they're very heavy, indeed, but I don't know how much they weigh.

他们负重确实很多,但是我不知道他们的负重是多少

耶鲁公开课 - 古希腊历史简介课程节选