35．Applications put computers to pratical
题型：单项选择题
问题：
| 35．Applications put computers to pratical 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 kernal provides all the functions for applications. The kemal (4) memory, I/O devices and parcels out processor time. The kernel also supports security and fault (5) , which is the ablity to recover automatically when parts of the system fail. |
(4)
A．understand
B．understands
C．understanding
D．understood