Obama's $3.6 trillion budget for the 2010 fiscal year beginning Oct. 1 contains ambitious programs to overhaul the US health care system and initiate new "cap-and-trade" rules to combat global warming.
Cap这个词我们最熟悉的意思是“帽子”,而在cap-and-trade这个表达当中,cap表示the upper limit on what is allowed,即“(允许的)上限”,比如,“薪水上限”pay cap,“价格上限”price cap等。上面报道中提到的“限制温室气体排放总量”也就是to cap the emission of greenhouse gases或者greenhouse gas emission cap。