I hope ____ ____ a doctor someday.
① ____ A. mine B. my C. your
② ____ A. hers B. you C. yours
③ ____ A. their B. ours C. our
若要使房子周围的门窗都朝南,房子只能建在( )
某车以相同的功率在两种不同的水平路面上行驶,受到的阻力分别为车重的k1和k2倍,最大速率分别为v1和v2,则( )