than rice grown under normal conditions. However, vitamin E levels increased by about 13 percent on average.

　　The researchers said the effects of planet­warming gases would be most severe 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 about 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. And scientists are finding that rising levels of carbon dioxide and other planet­warming gases threaten food quality.

　　Earlier studies showed that wheat, rice, field peas and soybeans grown under high carbon dioxide conditions all had lower levels of protein and minerals. 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.

　　【解题导语】　本文介绍了温室气体如何减少粮食作物中的营养物质以及降低气候变化对营养物的损害的方法。

　　5．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

　　B　解析：细节理解题。根据第二段中的"Rice grown under high carbon dioxide conditions had, on average, 13 to 30 percent lower levels...less protein(蛋白质)．"可知， B项为正确答案。A、C、D三项的表述均与原文表述不符。

　　6．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.

　　D　解析：细节理解题。根据文章最后一句"That is to grow different forms of rice that can adapt to higher carbon dioxide levels．"可知， D项为正确答案。

　　7．What's the author's purpose of writing the text?

A．To inform readers what nutrients food crops contain.