TPO 6 William smith 第八題 - 英檢

As he collected fossils from strata throughout England, Smith began to see
that the fossils told a different story from the rocks. Particularly in the
younger strata, the rocks were often so similar that he had trouble
distinguishing the strata, but he never had trouble telling the fossils
apart. While rock between two consistent strata might in one place be shale
and in another sandstone, the fossils in that shale or sandstone were always
the same. Some fossils endured through so many millions of years that they
appear in many strata, but others occur only in a few strata, and a few
species had their births and extinctions within one particular stratum.
Fossils are thus identifying markers for particular periods in Earth's
history.

According to paragraph 4, it was difficult for Smith to distinguish rock
strata because

A. the rocks from different strata closely resemble each other
B. he was often unable to find fossils in the younger rock strata
C. their similarity to each other made it difficult for him to distinguish
one rock type from another
D. the type of rock between two consistent strata was always the same


答案是A

我選C

請問C選項錯誤的地方在哪呢??

感謝解惑!!!

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