题目

He was        tired        he could not go on walking. A. too; to                        B. such; that                            C. so; that 答案：C超导材料的应用具有十分诱人的前景．假如科学家已研制出室温下的超导材料．你认为它可作下列哪种用途（ ）A．自炽灯泡的灯丝B．电炉中的电阻丝C．保险丝D．远距离输电线