某学生要在暑假去欧洲旅行，下面行程不可能的是（    ）

①第一届中国人民政治协商会议的召开

②西藏和平解放

③抗美援朝战争爆发

④土地改革在全国范围内基本完成

This is my day

    I am a doctor. I work at night. I go to work at 6:30 p. m. I eat dinner at 9:30. I usually go home at 8:00 in the morning. After breakfast, I go to bed at 9:10 a. m. I usually get up at 2:30 in the afternoon. I eat lunch at 3:00 in the afternoon. Then I play sports at 4:00 in the afternoon.

    This is my day. I enjoy my life.

将表面被氧化的铜片和铁片，同时加入足量稀盐酸中，除尽氧化膜。再经充分反应后，溶液中一定含有的金属离子是（   ）