As they migrate（迁移) , butterflies and moths choose the winds they want to fly with, and t

As they migrate（迁移) , butterflies and moths choose the winds they want to fly with, and they change their body positions if they start floating in the wrong direction. This new finding suggests that insects may employ some of the same methods that birds use for traveling long distances. Scientists have long thought that insects were simply at the mercy of the wind.
Fascinating as their skills of flight are, migrating behavior has been difficult to study in insects because many long distant trips happen thousands of feet above ground. Only recently have scientists developed technologies that can detect such little creatures at such great heights.
To their surprise, though, the insects weren't passive travelers on the winds. In autumn, for example, most light winds blew from the east, but the insects somehow sought out ones that carried them south and they positioned themselves to navigate directly to their wintering homes.
Even in the spring, when most winds flowed northward, the insects didn't always go with the flow. If breezes weren't blowing in the exact direction they wanted to go, the insects changed their body positions to compensate. Many migrating birds do the same thing.
The study also found, butterflies and moths actively flew within the air streams that pushed them along. By adding flight speeds to wind speeds, the scientists calculated that butterflies and moths can travel as fast as 100 kilometers an hour. The findings may have real-world applications. With climate warming, migrating insects are growing in number. Knowing how and when these pests move could help when farmers decide when to spray their crops.
【小题1】 What's the main idea of the text?A．Windsurfing insects have real direction.B．Wind helps insects greatly in migrating.C．Insects migrate with the seasons.D．Scientists have trouble in observing insects.【小题2】Scientists originally thought that .A．insects were just blown about by the windB．insects chose the winds they wanted to rideC．insects always waited for their favourable windsD．insects positioned themselves in the winds【小题3】 It is not easy to study the migrating behavior of the insects because .A．the little creatures can fly very fastB．their flight is long and high above groundC．the wind's direction is hard to foreseeD．they have no regular migrating courses【小题4】 We can learn from the text that .A．insects never position themselves when flying lowB．insects travel more easily in autumnC．insects fly in the way birds doD．insects rest a lot when the wind pushes them alongA【小题1】A【小题1】B【小题1】C

(答案→)A【小题1】A【小题1】B【小题1】C 解析：可联系答.案.网客服索取。

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