—China's first large passenger plane C919 flew successfully on May 5.
—Yes. What's more, it was built on our own in Shanghai.
A:with some help
B:from our friends
C:by ourselves
观察下列顺序排列的等式:
9×0+1=1
9×1+2=11
9×2+3=21
9×3+4=31
9×4+5=41
…
根据数表所反映的规律,猜想:第n个等式(n为正整数)应为( )
在设计探究实验时,下列不能作为一组对照实验的是( )