22．One reason why dinosaurs died out is that________.
A．there were too many dinosaurs
B．parts of the earth became cold and dry
C．the dead forests there could not supply them with enough food
D．they couldn't find enough to eat
答案 D 细节理解题。根据第一段的最后两句可知。
23．We can see from this passage________.
A．scientists are trying to make some dinosaurs
B．dinosaurs are dangerous enough
C．dinosaurs are worth studying further
D．scientists know nothing about dinosaurs
答案 C 细节理解题。根据第三段中的“Scientists are trying to make more discoveries about dinosaurs.”可知。
