求gmat 一题逻辑题。脑袋想疯了！！

Jimmyfish2012

Which of the following most logically completes the passage?

Most bicycle helmets provide good protection for the top and back of the head, but little or no protection for the temple regions on the sides of the head. A study of head injuries resulting from bicycle accidents showed that a large proportion were caused by blows to the temple area. Therefore, if bicycle helmets protected this area, the risk of serious head injury in bicycle accidents would be greatly reduced especially since _________.                                    

                                    

• Aamong the bicyclists included in the study's sample of head injuries, only a very small proportion had been wearing a helmet at the time of their accident
• Beven those bicyclists who regularly wear helmets have a poor understanding of the degree and kind of protection that helmets afford
• Ca helmet that included protection for the temples would have to be somewhat larger and heavier than current helmets
• Dthe bone in the temple area is relatively thin and impacts in that area are thus very likely to cause brain injury
• Ebicyclists generally land on their arm or shoulder when they fall to the side, which reduces the likelihood of severe impacts on the side of the head
  

D看了答案，我也能理解了。 但是b我还是想不通。 因为头盔保护太阳穴了，所以太阳穴部损伤就减少了。 那是因为经常戴头盔的人也不知道头盔不保护太阳穴，所以有必要加上保护，给头部一起保护起来。不对吗？
D我为什么排除，因为一开始是说head injury， 那我理解是脸部太阳穴擦伤（因为没有保护), 但是选项又变成会引起大脑损伤。 我觉得head injury和brain injury是两回事吧！！！！

kluivert

b 即便是经常带头盔的人对于头盔所带来的什么样的保护，什么程度的保护都知之甚少

举个例子，开车系安全带。无论你是否了解安全带的作用有多大，对系安全带对你实际的保护都没有任何的影响

Jimmyfish2012

谢谢