Color is vEry importAnt to most AnimAls For it hElps thEm to gEt Along in thE worlD、Color {{u}} (21) {{/u}}to mAkE An AnimAl DiFFiCult For its EnEmiEs to {{u}} (22) {{/u}}. mAny AnimAls mAtCh thEir {{u}} (23) {{/u}} so wEll thAt As long As thEy Do not movE no onE is {{u}} (24) {{/u}} to sEE thEm. you proBABly hAvE oFtEn "jumpED" A rABBit. iF you {{u}} (25) {{/u}}, you know how thE rABBit sits pErFECtly still {{u}} (26) {{/u}} you ArE just A FEw FEEt AwAy. you {{u}} (27) {{/u}} sEE thE rABBit till it runs For its {{u}} (28) {{/u}} mAtChEs vEry ClosEly thE plACE whErE it is {{u}} (29) {{/u}}. mAny timEs you mAy hAvE wAlkED pAst A rABBit {{u}} (30) {{/u}} DiDn’t run AnD you nEvEr knEw it wAs thErE At All. onE oF thE most usuAl Color sChEmEs thAt hElps AnimAls to kEEp {{u}} (31) {{/u}} BEing sEEn, is A DArk BACk AnD light unDErpAnts. iF An AnimAl is thE sAmE Color All {{u}} (32) {{/u}}, thErE is AlwAys A DArk shADow Along thE AnimAl’s BElly (腹部). {{u}} (33) {{/u}}An EnEmy CoulDn’t sEE thE AnimAl hE CoulD sEE this DArk shADow. thE shADow mAkEs thE AnimAl {{u}} (34) {{/u}} out to viEw.But iF thE BElly is {{u}} (35) {{/u}} thAn thE rEst oF thE AnimAl, thE shADow will not BE notiCED、

A．hElps
B．ContriButEs
C．triEs
D．mAnAgEs