缩句。   
1．轻快灵活的小艇穿过一座座形式不同的石桥。   
                                                                                                                     
2．许多孩子高高兴兴地到郊外去呼吸新鲜空气。  
                                                                                                                     
3．簇拥在一起的小艇一会儿就散开了。