题目内容：

阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

In September, in Britain, you may see a lot of swallows. They are gathering together because, very soon, they will be flying south to much 1. (warm) lands, where they will find plenty of small flying insects on 2. they feed. There are no such insects about in Britain during the winter, as it is too cold 3. them.

The swallows settle, fly off, dash, and settle again. This they do many times, for they are making short practicing 4. (flight) in order to be fit for the long journey ahead of them.

Flocks of these 5. (migrate) birds leave Britain in the autumn. They fly 6. (steady) for hundreds of miles before they reach the warm lands of Africa. But not all the birds get there, for many of them die in the 7. (storm) weather they meet with on the way.

In the spring of the following year they make the long and tiring journey back to Britain. They get 8. (settle) on the same barn or tree in the same district which they 9. (leave) the previous autumn.

Nobody knows exactly how these birds find their way there and back over such vast distance, but it has something 10. (do) with winds and air currents.