有关塑钢门窗特性的描述,不正确的是()。
A、绝热保温性能好
B、防腐性能好
C、外表美观,虫不蛀
D、气密性、水密性、隔声性能较差
参考答案:D
Assume that an operating system uses a round—robin scheduler. The process's quantum is 20 msec, and the context switch is 5 msec. What percentage of the CPU's time is spent on administrative overhead ( )
A.5%
B.15%
C.20%
D.25%
按提单中收货人栏的填写方式划分,提单的种类有()。
A.清洁提单
B.记名提单
C.指示提单
D.不记名提单
E.预借提单