-When did China __________ Shenzhou VII, do you remember?
-In September, 2008. The astronaut Zhai Zhigang took the Chinese first spacewalk.
A:send up
B:send out
C:put up
D:put out
已知:如图,D是△ABC的边AB上一点,CN∥AB,DN交AC于点M,MA=MC.①求证:AD=CN;②若∠BAN=90度,求证:四边形ADCN是矩形.
下列民族,由波斯人、阿拉伯人和汉、蒙、畏兀尔等民族逐渐融合而形成的是( )