A:二氧化硫
B:二氧化碳
C:二氧化氮
D:可吸入颗粒物
—Excuse me, sir, there is _____ tea in your cup, would you like some more? —Yes, please. And give me _____ mooncake. It tasted delicious.
一列车的质量是5.0×105kg,在平直的轨道上以额定功率3000kW不变加速行驶,当速度由10m/s加速到所能达到的最大速率30m/s时,共用了2min,则在这段时间内列车前进的距离是多少米?