题目

要将能分解纤维素的细菌从土壤中分离出来，应将它们接种在（    ） A．加入指示剂的鉴别培养基上                   B．含有蛋白胨的固体培养基上 C．只含纤维素粉而无其他碳源的选择培养基上    D．含四大营养要素的培养基上 答案：C— Mr Right is a really kind person.—Yes. He always tries his best to help others ___________.A. in turn B. in all C. in need