题目内容：

阅读七选五

Trees around us are extremely important and have always been necessary for improving the human conditions. Our existing forests and trees we plant work to make a better world. 1.. Here is a short list of main reasons trees are necessary for improving our living conditions.

●Trees produce oxygen

2.. A leafy tree produces as much oxygen in a season as 10 people inhale in a year. What many people don't realize is that the forest also acts as a giant filter (过滤器) that cleans the air we breathe. Trees help clean the air by preventing airborne particles, reducing heat, and absorbing such pollutants.

●Trees clean the soil

The term phytoremediation is a fancy word for the absorption of dangerous chemicals and other pollutants that have entered the soil. 3.. Trees filter sewage and farm chemicals, reduce the effects of animal wastes, clean roadside spills and so on.

●Trees are carbon sinks

To produce its food, a tree absorbs and locks away carbon dioxide in the wood, roots and leaves. Carbon dioxide is a global warming suspect. 4.. This locking­up process “stores” carbon as wood and not as a “greenhouse” gas.

●5.

Trees block urban noise almost as effectively as stone walls. Trees, planted at strategic points in a neighborhood or around your house, can reduce major noises from freeways and airports.

A．We could not exist as we do if there were no trees

B．Trees help clean the sky

C．A forest is a carbon storage area that can lock up as much carbon as it produces

D．Trees control noise pollution

E．Man has been planting trees to make the planet a more beautiful world

F．The modern human community has other more practical reasons to admire and honor trees

G．Trees can either store harmful pollutants or change the pollutants into less harmful forms