阅读下面短文，把A-D 四个句子填入文中空缺处（1-4 ），使短文内容完整正确。并完成第5小题。
Have you seen Jurassic Park (侏罗纪公园)? In this film, __1__ They have much trouble, however,
they realize that the cloned dinosaurs are smarter and fiercer (凶猛) than expected. __2__ In theory?
Yes. What would you need to do this? A well-preserved source (来源) of DNA from the extinct (绝种
的) dinosaur, and a closely related species (物种), still living now, that could be used as a surrogate (代
孕) mother. In reality? Probably not, __3__. However, __4__.
A. Could we really clone dinosaurs?
B. scientists have been trying to make their dream come true.
C. scientists use DNA preserved (被保存) for tens of millions of years to clone dinosaurs.
D. because dinosaur DNA couldn't survive (存活) for such a long time.
5. In order to clone some animal, scientists need _____.
A. some DNA
B. a surrogate mother
C. a laboratory
D. all the above
