[解析]
71:答案:May 24(th);细节理解题;根据短文内容第一行March 24th,可知作者在3月24号有过学校旅行,故填May 24(th);
72:答案:the Dashan Collection House;细节理解题;根据短文内容we had a school trip to the Dashan Collection House,可知作者去了"大山的藏书楼";故填the Dashan Collection House;
73:答案:(many) pictures;细节理解题; 根据短文内容And then in the Art Room,we saw many pictures of the countryside可知作者在艺术室看到了许多照片;故填(many) pictures;
74:答案:four;细节理解题;根据短文内容"When we entered the collection house,our eyes were caught by a collection of old photos of the town on the walls of the front hall""we saw many pictures of the countrysid""there were over one hundred different clocks""there was also a stone collection"可知文章提到了4种收藏品;故填four.
75:答案:two and a half hour/2.5 hours;细节理解题;根据短文内容"school bus and arrived at 9:00"和"they stayed there until 11:30in the morning"可知他们在那儿待了两个半小时;故填two and a half hour/2.5 hours.