单项选择题
Chinese musical instruments have a long history. According to statistics, the number of musical instruments mentioned in the Book of Songs are ( ). A. 20 B. 22 C. 25 D. 29
判断题 建立会计科目是先建立末级科目再建立上级科目。
单项选择题 直接采用流程图进行编程的PLC语言是( )。
单项选择题 （）是电脑验光仪物镜与被检者角膜顶点的距离。 A. 15mm B. 12mm C. 10mm D. 8mm
