题目

2,4-D是一类广泛应用于单子叶作物田间的除草剂,其大量施用导致土壤污染。某研究小组欲从2,4-D污染土壤样品中筛选2,4-D降解菌株,采集土样后进行如图操作:富集培养1组培养液成分:基础无机盐培养液+葡萄糖+2,4-D富集培养2组培养液成分:基础无机盐培养液+2,4-D基础无机盐培养液成分:MgSO4、(NH4)2SO4、FeS4、KH2PO4,Na2HPO4回答下列问题。(1)微生物实验要严格防止杂菌污染,划线纯化时对接种环可采用________灭菌。(2)在特定环境中只让一The boys played so carelessly in the game yesterday,_______ ,they lost the game.     A. as a result of  B. at the end   C. as a result D. to the end  
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