【环境保护】湟鱼是青海湖独有的鱼类，生活在咸水中，每年春夏之交，洄游到淡水河中产卵繁衍。近些年来，随着经济发展、人口增加，当地人在布哈河上建坝截留河水，缓解当地水资源紧张局面。

说出布哈河上水坝对湟鱼生存的影响。

The Voice of China

    Many Chinese like watching The Voice of China, because the songs sound really good. My daughter, my wife and I like it, too. We watch the programme(节目) every Friday. Some famous singers like Wang Feng, Zhang Huimei, Na Ying, Harlem Yu are the coaches. The coaches listen to the songs, and find their favorite singers. They can listen to the singers , but they can't watch the singers sing . Then they teach (教) their favorite singers. The singers sing songs again. The Voice of China is to find the best voice.

已知集合A={﹣1，0，1，2}，B={﹣2，1，2}，则A∩B=（　　）