关于OG11-78

OG11-78;OG10-158.

In comparison to the standard typewriter keyboard, the EFCO keyboard, which places the most-used keys nearest the typist’s strongest fingers, allows faster typing and results in less fatigue, Therefore, replacement of standard keyboards with the EFCO keyboard will result in an immediate reduction of typing costs.

Which of the following, if true, would most weaken the conclusion drawn above?

(A) People who use both standard and EFCO keyboards report greater difficulty in the transition from the EFCO keyboard to the standard keyboard than in the transition from the standard keyboard to the EFCO keyboard.

(B) EFCO keyboards are no more expensive to manufacture than are standard keyboards and require less frequent repair than do standard keyboards.

(C) The number of businesses and government agencies that use EFCO keyboards is increasing each year.

(D) The more training and experience an employee has had with the standard keyboard, the more costly it is to train that employee to use the EFCO keyboard.

(E) Novice typists can learn to use the EFCO keyboard in about the same amount of time it takes them to learn to use the standard keyboard.

这题我做的也是选D，但是看OG的B项解释突然迷糊了：

这题我攻击的是换用EFCO不一定能迅速使成本降低。OG攻击的条件是EFCO能使成本上升。

它对B的解释是生产成本和一般打字机的成本一样，则短期内的成本不会上升，所以不能削弱，但是我想的是只要不会导致EFCO成本降低，用EFCO后成本不变或者上升都是可以削弱的，B说用EFCO的短期成本与没用之前是一样的，不是也能削弱么

请NN们帮忙~

B is supportive of conclusion

能不能说的具体一点呢？

我赞同它说的较少的修是长期成本的减少，和文中immediate reduction没有关系。

那不比一般的键盘贵不能说明它就便宜啊~~~怎么加强结论啊

这道题不是weaken么。。。题目说换成EFCO可以立刻降低成本。B是EFCO不比普通的贵而且维修次数少，D是对于普通打字机越熟悉的员工花在培训使用EFCO打字机上的时间就越多，那么要weaken这个结论，应该就选D么~

看看这么解释行不行呢？