Hermitcrabs（寄居蟹）livetheirlivesintemporary，second-handaccommodation．Asthehermitcrabgrows，itmustfindalargershellfor（61）（protect）．Ifashellistoosmall，thecrabwillnotbeabletomovebackfullyinto

Question

Hermit crabs （寄居蟹） live their lives in temporary，second-hand accommodation．As the hermit crab grows，it must find a larger shell for （61）___（protect）．If a shell is too small，the crab will not be able to move back fully into it and therefore becomes （62）___easy target of its enemies．
Competition（63）___empty shells can be quite fierce among hermit crabs，especially if the supply is limited．Sometimes，however，the crabs form orderly"chains"，waiting patiently for some （64）___（hour）to obtain a shell of the right size．
This process begins with a single hermit crab leaving its own shell（65）___（inspect） a nearby empty shell for size．If the shell is too large，the crab will return to （66）___（it） own shell and wait close to the empty shell．As new crabs arrive，they repeat the inspection process．
If the new home （67）___（prove） unsuitable，they will return to their shells to wait in a queue．
（68）___（amaze），the crabs order themselves in this waiting chain，（69）___may consist of up to 20 individuals，from the largest to the smallest!When a crab claims the empty shell，all the individuals in the queue quickly exchange their shells in order，each crab （70）___（move） up to the next-sized shell!．

Answer 1

61．protection 考查名词．for是介词，后接名词作其宾语，动词protect的名词是protection．
62．an 考查冠词．target是可数名词，其前加不定冠词a表示泛指，因easy的读音是以发元音开头的，用不定冠词an．
63．for 考查介词．for意为"对于，在…方面"．
64．hours 考查名词．hour是可数名词，其前有some修饰时要用复数形式．
65．to inspect 考查动词不定式．此处动词不定式表示目的．
66．its 考查代词．shell是名词，其前要用形容词性物主代词作定语．
67．proves 考查动词时态．在条件状语从句中，主句用一般将来时态，从句用一般现在时态，因主语home是单数三人称，谓语动词也应用单数三人称形式．
68．Amazingly 考查副词．修饰句子要用副词，动词amaze的副词是amazingly．
69．which 考查定语从句．分析句子结构可知这是一个定语从句，先行词是chain，在从句中作主语，用关系代词which．
70．moving 考查现在分词．each crab与move之间是主谓关系，用现在分词构成独立主格结构．