Why did the author say that the bodies of the men　were twisted and wounded　in invisible way， according to Para. 2?

A.Heavy lifting had given many of them spinal problems　and appalling injuries.

B.The fathers always seemed older than the　mothers.

C.Some had broken ribs and lost fingers.

D.Some had partial vision loss as the glow of the welding　flame damaged their optic receptors.

正确答案：The fathers always seemed older than the　mothers.