System类的getProperties()方法的作用是（）

System.getProperties()的作用是

System.getProperties()方法可以获取操作系统的属性

System类的getProperties()方法的作用是（） A: 获取当前的操作系统的属性 B: 获取当前JVM的属性 C: 获取指定键指示的操作系统属性 D: 获取指定键指示的JVM的属性

Two systems of weights and measures used in the U.S. are ______. A: the U. S. Customary System and the metric system B: the International System and the metric system C: the Imperial System and the metric system D: the Customary System and the Imperial system

Starting system and ignition system belong to the electrical system？

What does the autopilot system include?? Hydraulic system|Mechanical system|Electrical system|All of above

The Atlantic Ocean is ( ). A: a closed system B: an open system C: an isolated system D: a homogeneous system

Engine system includes __________________, starting system, __________________ cooling system, fuel supply system, crank-connection rod mechanism and __________________.

What’s the type of the control system on CFM56-3 engine? ( ) A: pneumatic mechanical system B: EEC system C: FADEC system D: hydro-mechanical system