非电气化区段电气集中站常用的轨道电路为()轨道电路。
A.JZXC--480型交流
B.JZXC--480型直流
C.JZXC-H62型交流
D.JZXC-H18型交流
参考答案:A
For users, microkernel technology promises (90) , compact and sophisticated operating systems that are typically (91) across a range of hardware platforms. These operating systems will be customizable to let users run multiple operating system and application "personalities" on top of a single microkernel (92) . Microkernel based systems can provide this flexibility because the core operating system functions are (93) from the large number of utilities, features and extensions that are layered on top of them. As a result, updating and maintaining operating system is easier, since developers don’t have to modify the (94) every time they must acid a new feature.
A.bases
B.foundations
C.systems
D.foundation
与显示相关的Applet方法有【 】(),repaint()和update()。