何谓高频调幅电路？
Among the basic categories of equipment, which of the following are used to convert the hydraulic energy into linear motion?（） ["Hydraulic pumps","Valves","Hydraulic cylinders","Hydraulic motor"]
以下关于过程叙述中正确的是（） ["使用Call语句能调用Sub子过程，也能调用Function函数过程","子过程名和函数过程名都有值，也都有类型","过程的递归调用不能提高程序的执行效率","Sub子过程必须使用Call语句调用"]
A “strongback” refers to a（）. ["bar securing a cargo port","centerline vertical bulkhead","deep beam","spanner stay"]
下面不属于表现媒体的是（）。 ["打印机","光纤","键盘","音箱"]
KZ―列共―DJJ―Q用于发车方向（）调车信号机的按钮继电器励磁电路。
