What are three characteristics of NSC technology? （）(Choose three.)
ANSC operates at the file level.
BNSC operates at the byte level.
CNSC uses hard drives to store longer patterns.
DNSC retains learned patterns for a longer time.
ENSC is available only on platforms with dual hard drives.
6阶有限群的任何子群一定不是（ ）阶。
A、2
B、3
C、4
D、6
Given that the current directory is empty， and that the user has read and write privileges to the currentdirectory， and the following： Which statement is true？（）
A、 Compilation fails.
B、 Nothing is added to the file system.
C、 Only a new file is created on the file system.
D、 Only a new directory is created on the file system.
E、 Both a new file and a new directory are created on the file system.
What are two types of WebView monitoring statistics on the WX/WXC platforms?（） (Choose two.)
ALAN
BQoS
Ctraffic
DIPSec
在自然数集N上，下面哪种运算是可结合的？（ ）。
A、a*b＝a－b
B、a*b＝max{a，b}
C、a*b＝a＋2b
D、a*b＝｜a－b｜
判断下列命题的真假，并说明理由。 （1）如果（A∨C）⇔（B∨C），则A⇔B； （2）如果（A∧C）⇔（B∧C），则A⇔B； （3）如果﹁A⇔﹁B，则A⇔B。
