But the sight of workers wearing white protective suits and gloves hauling in tons of oil-contaminated waste - including bags of sandy tar balls, vegetation,used oil booms, rags and other clean-up supplies - has caused alarm among some Gulf coast communities.

VOA: standard.2010.08.05

So, 13 backscattered. TAs, if you can maybe pick up these ping-pong balls for me.

把这些球捡起来，我觉得如果，我摔倒一定很搞笑。

麻省理工公开课 - 化学原理课程节选