(2013·湖北，22)Carbon dioxide, which makes a between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is being warmer.
A. difference
B. parison
C. connection
D. barrier
网友回答
A. difference
B. parison
C. connection
(答案→)D. barrier
解析：句意：二氧化碳，在我们与太阳之间设置了一道屏障，阻止热量轻易地散发到大气层中，因此地球正变得更暖和。A项意为“区别，不同”；B项意为“对比，比较”；C项意为“联系”；D项意为“障碍，屏障”。故选D项。