求教: GWD 2 6

qwrersaa

e figure above shows the dimensions of a semicircular cross section of a one-way tunnel. The single traffic lane is 12 feet wide and is equidistant from the sides of the tunnel. If vehicles must clear the top of the tunnel by at least ½ foot when they are inside the traffic lane, what should be the limit on the height of vehicles that are allowed to use the tunnel?

A. 5½ ftB. 7½ ft .8 1/2FTd 9½ ftE. 10 ft

robert

这个题答案不是A，因为我查到这个题来自 GWD第2套，原题有图，半圆的直径为20 .

所以答案应该是B。

根据半径和路宽算出高度为8，8 -1/2 = 71/2

qwrersaa

how to reach a??

robert

A

[此贴子已经被作者于2005-1-12 16:00:17编辑过]