A:千锤万凿出深山
B:雪融山顶响流泉
C:吹尽狂沙始到金
D:蜡炬成灰泪始干
世锦赛游泳冠军宁泽涛比赛时所受的浮力约为( )
已知代数式x+2y的值是2,则代数式2x+4y﹣1的值是( )
Come on! The train is leaving, or we'll miss it.