Contact us
Choose a category below so we can get back to you as quickly as possible.
設火車全長x米,速度v米每秒 x+990=65v x=10v 解得x=180米v=18米每秒 火車180米速度18米每秒
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.