专题02 阅读理解1-冲刺2024年中考英语必考题型终极预测（深圳专用）.pdf

冲刺2024年中考英语必考题型终极预测（深圳专用）

专题02阅读理解

（2022・广东•深圳市南山外国语学校集（团）二模）

Apairoftusks长（牙）isusuallyanadvantageforelephants,allowingthemtodigforwater,peelbark

剥（树皮）forfoodandprotectthemselves.Butbecauseofillegallyhunting,thosebigtusksmayinvitedanger.

NowresearchersarcworkingouthowyearsofcivilwarandhuntinginMoambiquehaveledtoagreater

numberofclcphiintsthatwillneverdeveloptusks.

Duringthewarfrom1977to1992,fightersonbothsideskilledelephantsforivorytoprovidefundfor

thewar.IntheGorongosaNationalPark,around90%oftheelephantswerekilled.Thesurvivorsshareda

keyfeature:halfthefemaleswerenaturallyluskless—theysimplyneverdevelopedtusks—whilebefore

thewar,lessthanafifthlackedlusks.Moreconfusing,two-ihirdsofthenew-bornelephantswerefemale.

Likeeyecolorinhumans,genes基（因）areresponsibletorthis.Theyfoundthatthemothershave

producedthesmoking-gungenesforgeneticchanges.Theypassthechangedgenetobothsonsanddaughters,

butthesonsarclikelytodieearlyindevelopment.Daughtersstaybytheirmother,manygrowingtusklcss.

Mostpeoplethinkofdevelopmentassomethingthatgoesonslowly,buthumanscanspeeditup.When

wethinkaboutnaturalselection,wethinkaboutithappeningoverhundreds,orthousandsofyears,“said

SamuelWasser,ascientistattheUniversityofWashington.**Thefactthattusklessnesshappenedover15

yearsisoneofthemostsurprisingf^ndings.^^

Nowthescientistsarestudyingwhatmoretusklesselephantsmeanforthespecies物（种）andits

ki

environment.Thcchangeswilllastfbratleastquiteafewelephantgenerations.Ifanelephantdoesnthave

thetooltopeelbarkfromtrees,thenwhatchainreactionswi