二、选择答案 根据课文内容选择最佳选项。 1.Who knows how life began on the earth exactly? A. Scientists. B. Astronomers. C. No one. D. Aliens(外星人). 2.What does “small clever animals” in the last paragraph refer to? A. Insects. B. Reptiles. C. Dinosaurs. D. Humans.
C. No one.
D. Humans.