英语专四阅读练习题英语专四阅读练习题2017眼睛里没有追求的时候，一定是心如死灰的.时候。以下是小编为大家搜索整理英语专四阅读练习题2017，希望对正在关注的您有所帮助!更多精彩内容请及时关注我们应届毕业生考试网!Certainlynocreatureintheseaisodderthanthecommonseacucumber.Alllivingcreature,especiallyhumanbeings,havetheirpeculiarities,buteverythingaboutthelittleseacucumberseemsunusual.Whatelsecanbesaidaboutabizarreanimalthat,amongothereccentricities,eatsmud,feedsalmostcontinuouslydayandnightbutcanlivewithouteatingforlongperiods,andcanbepoisonousbutisconsideredsupremelyediblebygourmets??Forsomefiftymillionyears,despiteallitseccentricities,theseacucumberhassubsistedonitsdietofmud.Itisadaptableenoughtoliveattachedtorocksbyitstubefeet,underrocksinshallowwater,oronthesurfaceofmudflats.CommonincoolwateronbothAtlanticandPacificshores,ithastheabilitytosuckupmudorsandanddigestwhatevernutrientsarepresent.?Seacucumberscomeinavarietyofcolors,rangingfromblacktoreddish?browntosand?colorandnearlywhite.Oneformevenhasvividpurpletentacles.Usuallythecreaturesarecucumber?shaped—hencetheirname—andbecausetheyaretypicallyrockinhabitants,thisshape,combinedwithflexibility,enablesthemtosqueezeintocreviceswheretheyaresafefrompredatorsandoceancurrents.?Althoughtheyhavevoraciousappetites,eatingdayandnight,seacucumbershavethecapacitytobecomequiescentandliveatalowmetabolicrate—feedingsparinglyornotatallforlongperiods,sothatthemarineorganismsthatprovidtheirfoodhaveachancetomultiply.Ifitwerenotforthisfaculty,theywoulddevourallthefoodavailableinashorttimeandwouldprobablystarvethemselvesoutofexistence.Butthemostspectacularthingabouttheseacucumberisthewayitdefendsitself.Itsmajorenemiesarefishandcrabs,whenattacked,itsquirtsallitsinternalorgansintowater.Italsocastsoffattachedstructuressuchastentacles.Theseacucumberwilleviscerateandregenerateitselfifitisattackedoreventouched;itwilldothesameifthesurroundingwatertemperatureistoohighorifthewaterbecomestoopolluted.?1.Accordingtothepassage,whyistheshapeofseacucumbersimportant??A.Ithelpsthemtodigesttheirfood.?B.Ithelpsthemtoprotectthemselve