[问答题]
Suppose a car moves at constant speed along a hilly road. Wn+(9ugkpa otvs3nzcgc. )k5 ;here does the caruvm eh8* /wxy6 wgr,.n exert the greatest and, 8w .y/vemg*w6hxrun least forces on the road: (a) at the top of a hill, (b) at a dip between two hills, (c) on a level stretch near the bottom of a hill?
