题目内容：

Climate change will increase US wildfires,and the smoky air will cause terrible problems in areas far beyond those burned,reports an environmental group Thursday.

Two-thirds of Americans,or nearly 212 million,lived in states suffering from wildfire smoke three years ago,according to the report by the Natural Resources Defense Council(NRDC).These areas,which had smoke for at least a week,were nearly 50 times greater than those burned directly by fire.

“It affects a much wide area of the United States than people have realized.” says author Kim Knowlton,a Columbia University health professor,adding the smoke can move up to hundreds of miles.She says the smoke contains air pollution and can cause several kinds of diseases.

Texas was hit hardest in 2011,when smoke stayed for at least a week in areas that are home to 25 million people,according to NRDC’s report.Illinois,which recorded no wildfires within its borders,came second with

nearly 12 million people affected by smoke that moved in from elsewhere.The other eight states with the most people in touch with smoky air were,in descending order: Florida,Missouri,Georgia,Louisiana,Michigan,Alabama,Oklahoma and Iowa.

Nearly two dozen states had no wildfires within their borders in 2011,but eight of them still had at least one week of smoky air: Illinois,Missouri，Iowa,Kansas,Nebraska,Indiana,Wisconsin and Ohio.

Only 18 states and the District of Columbia had no people in touch with at least a week of smoke that year,although five of them—Alaska,California,Hawaii,Nevada and Utah—had a large area burned by wildfires.

The problem will only get worse.Knowlton says.Scientific research shows climate is causing higher temperatures and health problems.

1.We can learn from the first two paragraphs that_______.

A. climate change killed many Americans

B. there are fewer states burned by wildfires

C. every state had wildfire smoke for at least a week

D. most Americans suffered from wildfire smoke 3 year ago

2.Which of the following states had wildfires within its borders in 2011?

A. Iowa.    B. Kansas.    C. Ohio.    D. California.

3.The underlined word “descending” in the fourth paragraph probably means _______.

A. going down    B. coming true    C. looking practical    D. turning back

4.What is the text mainly about?

A. Climate change causes more wildfires.

B. Wildfire smoke becomes a serious health problem.

C. More wildfires cause climate changes.

D. Air pollution becomes a terrible problem.