[填空题]
A and B rowers, who can row xk:gecb b wjm;dw1: y12j5nc)at the sametbf /e4l.zkv* speed in still water, set off across a river at the same time. A heads straight across and is pulled downstream somewhat by the current. The B heads upstream at an angle so as to arrive at a point.fkez* bv/ l4t opposite the starting point. Which rower reaches the opposite side first?
参考答案: A
本题详细解析: Both rowers need to cover the same "cross river" distance. The rowve7i 2e doke6z) ;9ecger with the greatest speed in the "cross river" direction will be the one that reaches the other side first. The current has no bearing on t ke zovi6;gc)ee ed972he problem because the current doesn't help either of the boats move across the river. Thus the rower heading straight across will reach the other side first. All of his rowing effort has gone into crossing the river. For the upstream rower, some of his rowing effort goes into battling the current, and so his "cross river" speed will be only a fraction of his rowing speed.
