They pick up the garbage that builds up [=collects] along the highway.他们收捡公路上积下的垃圾。

Dust has begun building up on his piano.他的钢琴已经开始蒙上灰尘。

These dangerous chemicals are building up in our lakes and ponds.在我们的湖泊和池塘里这些危险的化学物质越来越多。

Political candidates are trying to build themselves up [=promote themselves] with public speeches and TV commercials.各位政治候选人正努力通过公共演讲和电视广告吹捧自己。

The movie was built up so much [=we heard so many good things about the movie] that we were disappointed when we actually saw it.这部电影被吹捧得太好了，所以我们真正看完以后觉得大失所望。