TOEFL Reading: ETS-TOEFL阅读机经 - H9J2AH7YX48887IVL$

Which of the following is presented in paragraph 5 as evidence that intense volcanic activity occurred at about the time that the dinosaurs became extinct A. The size of the volcanic craters on the Deccan plateau B. An increase in sea-floor spreading C. The formation in India of large amounts of a type of rock associated with volcanoes D. The occurrence of a thousand or more volcanic explosions the size of Krakatoa