已知信号如图所示，其表达式是()。 A: ε(t)+2.5ε(t-1)-s(6-4)( B: ε(t)+1.5ε(t-1)-2.5ε(t-4)( C: ε(t-1)+2.5ε(t-2)-1.5ε(6-4)( D: ε(t-1)-2.5ε(t-4)+1.5ε(t-2)

If the total weighted score of a company’s EFE matrix is greater than 2.5, it means that the company has greater external threats than opportunities.

中国大学MOOC: 写出下面程序执行后的运行结果。#include <stdio.h>struct STU {char name[10];int num;int Score;};int main(){struct STU s[5]={{"YangSan",20041,703},{"LiSiGuo",20042,580},{"wangYin",20043,680},{"SunDan",20044,550},{"Penghua",20045,537}},*p[5],*t;int i,j;for(i=0;i<5;i++) p[i]=&s[i];for(i=0;i<4;i++)for(j=i+1;j<5;j++)if(p[i]->Score>p[j]->Score){ t=p[i]; p[i]=p[j]; p[j]=t;}printf("%d %d",s[1].Score,p[1]->Score); return 0;}

已知二端网络N的端口电压u（t）=10sin（ωt+60°）V，端口电流i（t）=4sin（ωt+20°）A，则二端网络N的等效阻抗为（）。 A: 2.5Ω B: 2.5∠40Ω C: 2.5∠80Ω D: 40∠80Ω

下面代码的输出结果是()。 <?php $score=87; if($score>=90 && $score<=100){$grade="优秀";} if($score>=80){$grade="良好";} if($score>=70){$grade="一般";} if($score>=60){$grade="及格";} else{$grade="不及格";} echo $grade; ?>

Which of the following couldn't be used to show a student's education achievement?( ) A: mark B: grade C: score D: literature

以下参数传递正确的是： A: def score(mid_score, end_score): ……score(88, 79) B: def score( *，mid_score, end_score, mid_rate＝0.4): ……score(88, 79) C: def score( *，mid_score, end_score, mid_rate＝0.4): ……score(end_score = 79, mid_score = 88) D: def score( *，mid_score, end_score, mid_rate＝0.4): ……score(mid_score = 88, end_score = 79,0.5)

There are ________students playing basketball in the room. A: score of B: scores of C: two score D: two score of

若有定义int score&#91;10&#93;;，则对score数组中的元素的正确引用是（ ） A: score[10] B: score[6.0] C: score[0] D: score(7)

从学生成绩表SC中查询平均成绩大于60分的同学的学号和平均成绩的正确语句为： A: selectsno,avg(score)assscorefromscgroupbysnohavingavg(score)>60 B: selectsno,avg(score)assscorefromscgroupbysnowhereavg(score)>60 C: selectsno,avg(score)assscorefromscwhereavg(score)>60 D: selectsno,avg(score)assscorefromschavingavg(score)>60