黃金閱讀 William Smith - 英檢

題目原文第四段
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．
8.According to paragraph 4，it was difficult for Smith to distinguish rock strata because
○the rocks from different strata closely resembled each other
○he was often unable to find fossils in the younger rock strata
○their similarity to each other made it difficult for him to distinguish one rock type from
another
○the type of rock between two consistent strata was always the same

請教一下大家~這題答案是第一個 可是我選第三耶...哪裡錯了呢?

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