题目内容：

A new study shows that rising levels of planet-warming gases may reduce important nutrients（营养物质）in food crops

Researchers studied the effects of carbon dioxide on rice， In the experiment， scientists grew 18 kinds of rice in fields in China and Japan．They set carbon dioxide levels to what scientists are predicting for our planet by the end of the century．Rice grown under high carbon dioxide conditions had，on average，13 t0 30 percent lower levels of four B vitamins and 10 percent less protein（蛋白质）The crops also had 8 percent less iron and 5 percent less zinc than rice grown under normal conditions However， vitamin E leveLs increased by about 13 percent on average．

The researchers said the effects of planet-warming gases would be most sevcre for the poorest citizens in some of the least developed countries．These people generally eat the most rice and have the least complex diets．That includes abour 600 million people in Indonesia， Cambodia，Myanmar，Bangladesh，Laos and other nations，mainly in Southeast Asia．

Other studies have shown that higher temperatures from climate change and weather extremes will reduce food production．But scientists are finding that rising levcls of carbon dioxide and other planet-warming gases threaten food quality．

Earlier studies showed that wheat，rice，field peas and soybeans grown under high carbon dioxide conditions all had Iower levels of protein and mincrais．Scientists predicted that almost 150 million people might be at risk of having too little protein or zinc in their diet by 2050．

The new study suggests a way to lower the nutritional harm of climate change．That is to grow different forms of rice that can adapt to higher carbon dioxide levels．

1.Growing rice under high carbon dioxide conditions may____．

A. increase iron in the rice

B. make it less nutritious

C. cause losses of Vitamin E

D. make it more delicious

2.How can people reduce the nutritional harm of climate change？

A. By importing rice from China and Japan．

B. By taking other kinds of food instead of rice．

C. By avoiding eating rice from Southeast Asia．

D. By growing rice suitable for the environment．

3.What’s the author’s purpose of writing the text？

A. To infom readers what nurrients food crops contain．

B. To call on people to care for the planet they live on．

C. To share the results of some studies on people’s diets．

D. To tell readers where food crops are mainly produced．

4.In which part of a magazine can you read the text？

A. Advertisements．    B. Arts and culture．

C. Science report．    D. Business news．