牛津譯林版高中英語必修五unit 3《science and nature》ppt練習(xí)課件5-全文預(yù)覽
【正文】 lo n in g t e c h n ologies m igh t r e d u c e t h e t im e n e e d e d t o m ake a t r ans ge n ic a n im al m odel. Unit 3 Science and nature S t e m c e ll s ar e r e sp ons ib le f or d e ve lop i n g ， m ai n t ain in g and r e p air in g t h e b ody t h r ough out li f e .Re se ar c h e r s ar e c u r r e n t l y look in g u p c lon in g as a w ay t o c r e a t e ge n e t ica ll y d e f in e d h u m an s t e m c e ll s f or r e se ar c h and m e d ica l p u r p ose s. Have you see n Jur assic Park? In t h is f e at u r e f il m ， sc ientist s u s e DN A p r e se r ve d f or t e n s of m il li ons of ye ar s t o c lon e d in osa u r w e r e ally clone din osa u r s? In t h e or y? Y e w e ll p r e se r ve d sou r c e of DN A f r o m t h e e xt in c t d in osau r ， a n d a c losely r e lat e d sp e c ies ， c u r r e n t ly li vin g ，t h at c oul d se r ve as a su r r ogat e ( 替代的 ) m ot h e r . Unit 3 Science and nature In r e ality? Pr obab ly n ot .It ’ s n ot li k e ly t h at d in osau r DN A c oul d su r vive u n d am age d f or su c h a lon g t ime .How e ve r ，sc ientist s h ave t r ied t o c lon e sp e c ies t h at b e c a m e e x t in c t m o r e r e c e n t ly ， u si n g DN A f r o m w e ll 173。 ” ‘ ...i f I ___________ t h e c h ance ， I ___________ a c lon e d b aby r igh t n ow . ’ had woul d ha v e 2 ． whil e 引導(dǎo)讓步狀語從句 盡管克隆人類胚胎在很多國家還不合法 ， 但一些科學(xué)家已經(jīng)在加緊研究 ， 以制造出克隆的人類嬰兒。 c lon in g C ． n e ither of t h e w r ite r s ar e again st c lon in g D ． b ot h o f t h e w r ite r s ar e n ot f or c lon in g hu m an em b r yos 3 ． Th e a n n ou n c e m e n t of s u c c e ssf u l h u m an e m b r yo c lon in g h as c aus e d m u c h d e b at e b e c aus e _________ _
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