则其表面积为:(72×6+72×12+12×6)×2,
=(432+864+72)×2,
=1368×2,
=2736(平方厘米);
第二种排列方法1×2×6时,长方体的棱长分别为:12厘米,6×2=12厘米,6×6=36厘米,
则其表面积为:(12×12+12×36+12×36)×2,
=(144+432+432)×2,
—I will have an important test tomorrow. I feel stressed now.—__________ and believe youself. You will pass it.
有一则公益广告:一位母亲在为婆婆洗脚时,一个迈着蹒跚步子的小男孩端出一盆水来,水花四溅,他用稚嫩的童音说“妈妈,洗脚„„”这则广告启示人们( )
下列既有离子键又有共价键的化合物是 ( )