Theyhavenobrainsandnospines(脊椎).Youcanoftenseerightthroughthem.Buttheycancausepainfulsometimesdeadlystings(刺伤).Somecanevenglowinthedark!Scientistsknowthemasmedusasbutmostpeoplecallthemjellyfish.

Jellyfisharenotreallyfish.Jellyfishhavestomachsandmouthsbutnoheads.Theyhavenervoussystemsforsensingtheworldaroundthem.Theyaremadealmostentirelyofwaterwhichiswhyyoucanlookthroughthem.Mostjellyfishliveinsaltwaterapartfromafewtypesthatliveinfreshwater.Jellyfisharefoundinoceansandseasallovertheworld.TheyliveinwarmtropicalseasandinicewatersneartheNorthandSouthPoles.

Adultjellyfishareshapedlikeanopenumbrellaorabell.AJellyfishhastentacles(触须)attheedgesofitsbody.Atthecentreofajellyfish’sbodywhereitiswidestisthemouth.Theendsofthetentacleshavestingcellsonthemwhichjellyfishusetocatchtheirprey(猎物).Somejellyfishhavepowerfulstingsthatcankillpeople.

Mostjellyfisheatfishtinycreaturesandevenotherjellyfish.Onceajellyfishstingsandcatchesitspreyittakesthepreytoitsmouthandswallowsit.

Somejellyfishareveysmallnolongerthanamarble(弹子).Othersarequitelarge.Thelargestjellyfishcangrowtoabout7feet(about2meters)acrossandweighthundredsofpounds!Jellyfishmaybeblueorangepinkyellowpurpleandothercolours.

Somejellyfishcanglowinthedarkbymakingtheirownlight.Thelightismadebyachemicalreactioninsidethejellyfish.Scientistsbelievejellyfishglowforseveralreasons.Forexampletheymayglowtoattractanimalstheypreyon.

61. Whatisthesecondparagraphmainlyabout?

A.Whatjellyfishliveon. B.Whatjellyfishlooklike.

C.Howjellyfishmove. D.Whatjellyfishare.

62.Whatisinthecentreofajellyfish’sbody?

A.Itsbrain. B.Itsmouth.

C.Itsnervoussystem. D.Itsstomach.

63.Howdoesajellyfishcatchandeatitsprey?

A.Itstingsandcatchesitspreythensendsitintoitsmouthtochewit.

B.Itbitesthepreywithitsmouthchewsitwithitsteethandthenswallowsit.

C.Itstingstheprey