Mother lets me play football _____ I've finished homework. A.unlessB.untilC.only ifD.if only
Mother lets me play football _____ I've finished homework.
A.unless
B.until
C.only if
D.if only
相关考题：
A wise mother never ______ her children to the slightest possibility of danger. (A) exposes(B) makes(C) sends(D) lets
I _________ table tennis quite well, but I haven ’t had time to play since the New Year.A. will playB. have playedC. play
–– Jack: Mommy, when will we have dinner? I'm starving.–– Mother:————————? We have to wait for daddy.A: Quickly, honeyB: OK, honeyC: Soon, honeyD: All right, honey
I() ping－pang quite well, but I haven t had time to play since the new year. A、will playB、have palyedC、playedD、play
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=10a football is destroyed.a football is created.i=20a 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);}
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;