2014
高考英语阅读理解基础精品题练习（12）及答案阅读理解 global warming is when the earth heats up, the temperature rises. it happens when greenhouse gases ---carbon dioxide, water vapor, nitrous oxide(二氧化氮), and methane(沼气) trap heat and light from the sun in the earth’s atmosphere, which increases the temperature. this is like when heat is trapped in a car. on a very h
