题目内容：
根据下列题干，回答题：Applications put computers to practical business（1），but below the（2）it's the heart of an operating system-the kernel-that provides the technical wizardry to juggle multiple program，connect to networks and store（3）．
A traditional kernel provides all the functions for applications．The kernel（4）memory，I/O devices and parcels out processor time．
The kernel also supports security and fault（5），which is the ability to recover automatically when parts of the system fail．
请选择（1）处最佳答案：
参考答案：
答案解析：