問題詳情
【題組】35. According to the passage, the most dramatic change to the oceans caused by plankton duringthe Cretaceous period concerned
(A) the depth of the water
(B) the makeup of the sediment on the ocean floor
(C) the decrease in petroleum-producing sediment
(D) a decline in the quantity of calcareous ooze on the seafloor
參考答案
答案：B
難度：適中0.666667
統計：A(0),B(2),C(1),D(0),E(0)