Ⅰ.语言知识及应用(共两节，满分45分)
第一节 完形填空(共15小题；每小题2分，满分30分)
阅读下面短文，掌握其大意，然后从1～15各题所给的A、B、C和D项中，选出最佳选项。
One bright summer day，a number of little boys and girls were out walking with their teacher.They walked two by two，singing happily.
In their walk they came to a __1__ over the river，and they turned to go across it.They had just reached the middle __2__ there came a great shout behind them.The teacher told them to stop，and she __3__ and listened.When she heard the cry
