A.unless
B.until
C.only if
D.if only
第1题:
I_____ jogging every morning in the park.
A. go
B. do
C. play
第2题:
I _________ table tennis quite well, but I haven ’t had time to play since the New Year.
A. will play
B. have played
C. play
第3题:
(A) exposes
(B) makes
(C) sends
(D) lets
正确答案:A
解答参考:A.本题考查expose的用法。expose somebody to表示使某人接触……,使处于……影响下‖。【译文】明智的母亲绝不会让孩子们处于哪怕是一丁点的可能的危险当中。
第4题:
根据下列程序的执行结果,可以断定划线部分的修饰符应为______。执行结果:
i9a football is created.
a football is created.
i=10
a football is destroyed.
a football is created.
i=20
a football is destroyed.
a football is destroyed.
源程序:
include<iostream.h>
class Football
{
public:
Football( ){cout<<"a football is created."<<endl;}
~Football( ){tout<<"a football is destroyed."<<endl;}
};
void func(int i)
{
______Football f1;
Football f2;
cout<<"i="<<i<<endl;
}
void main( )
{
func(10);
func(20);
}
第5题:
–– Jack: Mommy, when will we have dinner? I'm starving.
–– Mother:————————? We have to wait for daddy.
A: Quickly, honey
B: OK, honey
C: Soon, honey
D: All right, honey
第6题:
After they finished _____football,they went for a drink in a pub.
A.playing
B.to play
C.play
第7题:
I've always enjoyed_____ football.
A. to play
B. playing
C. play
第8题:
A.me; me
B.me; has
C.I; am
D.I; is
第9题:
A、will play
B、have palyed
C、played
D、play
第10题:
B 宽度优先(种子染色法)
5.关键路径
几个定义: 顶点1为源点,n为汇点。
a. 顶点事件最早发生时间Ve[j], Ve [j] = max{ Ve [j] + w[I,j] },其中Ve (1) = 0;
b. 顶点事件最晚发生时间 Vl[j], Vl [j] = min{ Vl[j] – w[I,j] },其中 Vl(n) = Ve(n);
c. 边活动最早开始时间 Ee[I], 若边I由<j,k>表示,则Ee[I] = Ve[j];
d. 边活动最晚开始时间 El[I], 若边I由<j,k>表示,则El[I] = Vl[k] – w[j,k];
若 Ee[j] = El[j] ,则活动j为关键活动,由关键活动组成的路径为关键路径。
求解方法:
a. 从源点起topsort,判断是否有回路并计算Ve;