钢筋焊接用的氧气、乙炔及液化石油气等应符合相关标准。
参考答案：对
影响光盘老化的外在因素不包括（）。
A.光盘的写读功率
B.光盘的写读方式
C.记录结构
D.空气湿温度
E.空气污染物
________ the students in this school is about three thousand, and ________ of them are girls. [ ]
A. A number of; two third
B. The number of; two thirds
C. A number of; two thirds
D. The number of; two third
