A:For a swimming lesson, you need a swimsuit.
B:For a swimming lesson, you need a swimming cap.
7世纪前期,统一青藏高原并与文成公主成亲的少数民族首领是( )
“世界屋脊”上适合种植的粮食作物是( )
近似数0.5600的有效数字和精确度分别是( )
下列有关碳和碳的氧化物的说法错误的是( )