Last 2-4-2

Last 2-4-2

The teeth of some mammals show “growth rings” that result from the constant depositing of layers of cementum as opaque bands in summer and translucent bands in winter. Cross sections of pigs teeth found in an excavated Stone Age trash pit revealed bands of remarkably constant width except that the band deposited last, which was invariably translucent, was only about half the normal width.

The statements above most strongly support the conclusion that the animals died

(A) in an unusually early winter

(B) at roughly the same age

(C) roughly in midwinter

(D) in a natural catastrophe（C）

(E) from starvation

说夏天牙骨质不透明,冬天半透明.有一处发现的猪骨中,都是一样的宽,只是后面沉淀下来的是一半的宽.这就是俺的理解,不明白透明和宽度有什么关系?怎么得出的C?

"Cross sections of pigs teeth found in an excavated Stone Age trash pit revealed bands of remarkably constant width except that the band deposited last, which was invariably translucent, was only about half the normal width."

I guess you missed the word "translucent".  Translucent indicates that it was in winter.  "Half the normal width" suggests that it's half way through winter -- i.e. midwinter.

明白了。谢谢Robertchu!