21-25 A D A B B 21 A 和D 都没错啊..(多选?还是题出错了) A肯定对,D也没错。初中英语出题思路一般倾向A数字分析类22 D 第二段第三句明确指出 ... a metal box. This could hold water, or it could be empty. So they were able to change its weight23 A the balloon went higher. It went up to 3,000 metres, and the air was very cold.24 D finally land on POLAND. From London.25 B (这个不肯定啊..B和C之间,同问,求高人补充解释)