英语语法名词Idon'thaveany____withspokenEnglish,butIoftenmeetwith____inEnglishgrammar.A.difficulties...difficultyB.difficulty...difficultiesC.difficulty...difficultyD.difficulties...difficulties为什么答案是BTheystored___

　　英语语法名词

　　Idon'thaveany____withspokenEnglish,butIoftenmeetwith____inEnglishgrammar.

　　A.difficulties...difficulty

　　B.difficulty...difficulties

　　C.difficulty...difficulty

　　D.difficulties...difficulties

　　为什么答案是B

　　Theystored____foodandwaterinthecavetopreparefortheworst.

　　A.largequantitiesof

　　B.agreatmany

　　C.aplentyof

　　D.quitealot

　　为什么答案是A而不是C?