C:Goodevening,sir,Howmanypersons,please?H:Goodevening. 1..C:Haveyoumadea reservation ,sir?H:No, 2..C:I’mverysorry,sir.Allourtablesaretaken,it'sthepeakseason,youknow.Butifyou’d liketowait,youaremorethanwelcometodoso.H:Howlongdoyouthinkwe’llhavetowait?C: 3. .Wouldyoumindwaitinguntilitisfree?We’llseatyourpartyassoonas possible.H:Oh...Okay.C:Wouldyoupleasetellmeyourname,sir?H:Harrison.(After15minutes)C:Mr.Harrison?H:Yes.Here!C: 4. .We have a table for you now. Wouldyoupleasecomewithme?(Leadingthemtoatableinthehall) Isthistablefine withyou,Mr.Harrison?H:It'sOkay. 5.C:Allright.Pleasetakeyourseats.Yourwaiterwillbewithyouinaminute.H:Thanksalot. A: About 15 minutes. B: Butwepreferatablebythewindow. C: Is there a table for 7? D: I’m afraid not. E: I’msorrytohavekeptyouwaiting.

设.向量可表示为的线性组合:,则() A: a=-1,b=-1,c=-1 B: a=1,b=-1,c=-1 C: a=-1,b=1,c=-1 D: a=-1,b=-1,c=1

共有4个站进行码分多址通信。4个站的码片序列为：a：（-1 -1 -1 +1 +1 -1 +1 +1） b：（-1 -1 +1 -1 +1 +1 +1 -1）c：（-1 +1 -1 +1 +1 +1 -1 -1） d：（-1 +1 -1 -1 -1 -1 +1 -1）现收到这样的码片序列：（+1 +1 -1 +3 +1 +1 -3 +1），则（ ）发送1。 A: a和d B: a C: b和c D: c

A、B、C三个站点采用CDMA技术进行通信，A、B要向C发送数据，设A的码片序列为+1，-1，-1，+1，+1，+1，+1，-1。则B可以选用的码片序列为: -1，+1，-1，+1，-1，+1，+1，+1|-1，+1，-1，+1，-1，+1，-1，+1|-1，+1，-1，-1，-1，+1，+1，+1|-1，-1，-1，+1，-1，+1，+1，+1

下列哪个码片序列不能用于CDMA通信 A: ( -1 -1 -1 +1 +1 -1 +1 +1 ) B: ( -1 -1 +1 -1 +1 +1 +1 -1 ) C: ( -1 +1 -1 +1 +1 -1 -1 -1 ) D: ( -1 +1 -1 -1 -1 -1 +1 -1 )

点( 1,1, 1)对于z轴的对称点为( ) A: ( -1, -1, 1) B: ( 1, -1, -1) C: ( -1, 1, -1) D: ( -1, -1, -1)

设集合A={1,a},则P(A)=() A: {{1},{a}} B: {,{1},{a}} C: {,{1},{a},{1,a}} D: {{1},{a},{1,a}}

设 $A, B, C$ 是同阶可逆矩阵，则 $(ABC)^{-1}=$（ ）. A: $A^{-1}B^{-1}C^{-1}$ B: $C^{-1}B^{-1}A^{-1}$

共有 4 个站进行码分多址通信。 4 个站的码片序列为： a ：（ -1 -1 -1 1 1 -1 1 1 ） b ：（ -1 -1 1 -1 1 1 1 -1 ） c ：（ -1 1 -1 1 1 1 -1 -1 ） d ：（ -1 1 -1 -1 -

把十进制数55转换成二进制数为（ ）。 A: 1 1 0 1 1 0 B: 1 1 0 1 1 1 C: 1 1 0 1 0 1 D: 1 0 1 1 1