要锻造一件长100mm，宽60mm，高25mm的毛坯钢，需要截面积为50×50m

____ several times, but unfortunately, the boy still couldn’t smooth away the problem on his own.[ ]

A. Having been explained              

B. The problem having been explained

C. The problem had been explained

D. Although the problem had been explained

下列条件语句中，功能与其他语句不同的是( )。

A．if(a) printf("%d\n",x); else printf("%d\n",y);

B．if(a==O) printf("%d\n",y); else printf("%d\n",x);

C．if(a!=0) printf("%d\n",x); else printf("%d\n",y);

D．if(a==0) printf("%d\n",x); else printf("%d\n",y);

家庭收支管理以（）作为管理对象。

A.资产负债

B.流动负债

C.现金流

D.自有结余

[A] stamp
[B] zoo
[C] blackboard
[D] train
[E] post office
[F] park
[G] bank

People send a letter there.

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