数字电路中y′=(a′+b′c′)(c′+d′) =a′c′+b′c′+a′d′+b′c′d′ =a′c′+b′c′+a
如图,正方体ABCD-A′B′C′D′中,求证
如图所示,△ABC≌△A′B′C′,AD,A′D′为△ABC与△A′B′C′的中线,请说明AD=A′D′.
I have () holiday.A:two months B:two month′s C:two-month D:a
( )-(c-d)=(a-c)-(-b+d)
正方体ABCD-A′B′C′D′中,点E在AB′上,点F在BD上,且B′E=BF,求证:EF平行平面BB′C′C
物质A、B、C、D均为单质,物质A′、B′、C′、D′均为氧化物;A与A′、B与B′、C与C′、D与D′含有相同元素.它
There are trees.Let′s color them ( ) A:work B:bag C:green D:
Does Wang Yong ′s father teach ------music A,I B,we C,us D,o
已知正方体ABCD-A′B′C′D′中,对角线A′C与平面BC′D交于点O,AC、BD交于M,求证:C′、O、M共线.
如图(2),∠ABC=∠A′B′C′,BD,B′D′分别是∠ABC,∠A′B′C′的平分线, 求证∠1=∠2 证明
a b c d* d_________=d c b a
4.已知;如图,CD、C′D′分别是Rt△ABC、Rt△A′B′C′斜边上的高,且CB=C′B′