2013年职称英语理工类的A级阅读理解练习题4

　　Monarch without a Kingdom

　　This November, a hundred million butterflies will drop from the sky over Mexico, like autumn leaves. But for how long? Genetically modified maize could mean extinction for this beautiful butterfly, Rafael Ruiz reports.

　　In November, millions of Monarchs fall like bright, golden rain onto the forests in the mountains of central Mexico. In the silence of these mountains you can hear a strange flapping of wings, as the Monarchs arrive at their destination. In the mountains, which reach a height of 3,000 metres, the butterflies are safe.

　　These delicate creatures now face danger of another kind - from scientific progress. In the US, millions of farms grow genetically modified maize which is pure poison for the butterfly. Laboratory experiments have shown that half of the butterflies which feed on the leaves of genetically modified maize die within 48 hours. Not all experts agree that this variety of maize is responsible for the threat to the Monarchs. In spite of these doubts, the European Union has refused to approve new crops of genetically modified maize until further investigations have been carried out.

　　16 The Monarch butterfly travels 5,000 km each year.

　　17 The Monarch butterfly looks fragile.

　　18 The Mexicans like butterflies very much.

　　19 in bad winters, about 70 per cent of the butterflies can stay alive

　　20 In early April, the butterflies leave their winter homes flying back north

　　21 Genetically modified maize isnt poisonous to the butterflies.

　　22 Genetically modified products are not popular in Mexico

　　参考答案：16 A 17 A 18 C 19 B20 A 21 B 22 C