The pollutant will give off a lage ___ of heat.

英语全文帮忙翻译下,谢谢!
Whale Ear Wax Reveals Environmental Pollutants
Some whales build up waxes, lipids and keratin into earplugs that tell researchers about a whale's lifetime exposure to pollution. Cynthia Graber reports
Cerumen. It’s a lovely word. Especially considering that it means earwax. And we’re not the only species that produces the stuff. Some whales build up waxes, along with lipids and keratin protein into what’s called earplugs. And researchers now know that examining these plugs tells them about a whale’s lifetime exposure to pollution.
Alternating layers of dark and light in the plugs correlate to seasons of feeding or migration. So the plugs have been used to determine a whale’s age. Think tree rings.
In the latest study, scientists analyzed an earplug from an endangered blue whale killed by a ship near California. They found that levels of stress hormones doubled over the whale’s life.
They also found evidence that the whale had been exposed to pesticides such as DDT, with the highest levels during the whale’s first six months of life. The whale was likely exposed to the pesticides in its mother’s milk.
They also found a couple of peaks of exposure to mercury. The study is in the Proceedings of the National Academy of Sciences. [Stephen J. Trumble et al., Blue whale earplug reveals lifetime contaminant exposure and hormone profiles]
Future earplugs should offer additional clues about whale lives. So look for researchers to give new attention to leviathan cerumen.

求解一道逻辑题
Nitrogen dioxide is a pollutant emitted by automobiles.Catalytic converters,devices designed to reduce nitrogen dioxide emissions,have been required in all new cars in Donia since 1993,and as a result,nitrogen dioxide emissions have been significantly reduced throughout most of the country.Yet although the proportion of new cars in Donia’s capital city has always been comparatively high,nitrogen dioxide emissions there have showed only an insignificant decline since 1993.
Which of the following,if true,most helps to explain the insignificant decline in nitrogen dioxide emissions in Donia’s capital city?
A.More of the cars in Donia’s capital city were made before 1993 than after 1993.
B.The number of new cars sold per year in Donia has declined slightly since 1993.
C.Pollutants other than nitrogen dioxide that are emitted by automobiles have also been significantly reduced in Donia since 1993
D.Many Donians who own cars made before 1993 have had catalytic converters installed in their cars.
E.Most car trips in Donia’s capital city are too short for the catalytic converter to reach its effective working temperature.
我觉得这里没有答案,但官方给的答案是E,我认为E说的是catalytic converter是否能够有效的工作,原文没说他的工作有效性啊,

New laws are yet to be made to reduce pollutant release.
翻译一下,特别是那个yet什么意思