北京师范大学考博英语阅读真题精解.pdf

中国考博辅导首选学校 北京师范大学考博英语阅读真题精解 “I’ve never met a huma worth cloning,” says cloning expert Mark Westhusi from the cramped confines of his lab at Texas AM University. “It’s a stupid endeavor.” That’s a interesting choice of adjective, coming from a ma who has spent millions of dollars trying to clone a 13 year old dog named Missy.So far, heandhis teamhavenot succeeded,thoughtheyhave clonedtwocalves andexpecttocloneacatsoon.Theyjustmightsucceedi cloningMissy laterthisyear — orperhaps not for another five years.It seemsthe reproductive system of ma ’sbest friend isone of themysteries of moder science. Westhusi ’sexperiencewith cloninganimals leaveshim vexedby all this talk of huma cloning.I three years ofwork o theGeng duo yua xiao wa zheng kao bo ying yu zhe ti ji qi jie xi qing lia xi qua guo mia fei zi xu dia hua: si ling ling liu liu ba liu jiu qi ba ,huo jia zi xu qq: qi qi er liu qi ba wu sa qi Miss yplicity project, using hundreds upo hundreds of canine eggs, the AM team has produced only a doze or so embryos carrying Missy’s DNA.None have survived the transfer to a surrogatemother.The wastage of eggs and the many spontaneously aborted fetuses may be acceptable whe you’re dealing with cats or bulls, he argues, but not with humans. “Cloning isincrediblyinefficient,andalsodangerous,”he says. Eve so, dog cloning is a commercial opportunity, with a nice 中国考博辅导首选学校 research payoff.Ever since Dolly the sheep was cloned i 1997, Westhusi ’s phone at AM College of Veterinary Medicine has bee ringing busily.Cost is no obstacle for customers like Missy’s mysterious owner, who wishes to remai unknow to protect his privacy.He’s plopped dow $3.7 millio so far to fund the research because hewants a twi to carry o Missy’sfine qualities after she dies.But he knows her clone may not have her temperament.I a statement of purpose, Missy’s owners an