已知四边形ABCD是平行四边形，下列结论中不正确的有（　　）.

①当AB＝BC时，它是菱形；②当AC⊥BD时，它是菱形；③当∠ABC＝90°时，它是矩形；④当AC＝BD时，它是正方形．

不同国家，由于地理位置不同，自然环境和人文环境千差万别，读四国轮廓图（如图），完成下题。

B

    Mike works very long hours every day. He usually gets up at 17:00. He has a shower and makes his breakfast. What a funny time to make breakfast! After breakfast, he practices (练习) his guitar for ten minutes, then he puts on his jacket and goes to work. To get to work, he takes the No.17 bus to the Star Hotel. The bus usually leaves at 19:15. He works all night. People love to listen to him! He gets home at 7:00, and he watches the early morning news on TV. He goes to bed at 8:30, a tired but happy man. Can you think what his job is?

下表资料摘自联合国于2001年发布的预测报告，反映了2001—2050年世界移民趋势。以下关于该城市迁入人口的正确叙述是(　　)