TOEFL Reading: ETS-TOEFL阅读机经 - 8I6D4DNI2GYN37D0L$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. There are few fossils from the Precambrian, though more keep turning up. B. Most evidence of animals in the fossil record is indirect and little of it is from the Precambrian. C. Tunnels in Precambrian rocks that may have been made by worms provide indirect evidence of these animals existing at that time. D. There are very few fossils of animals from the Precambrian and most evidence of animal life from that period is indirect.