A:They were not nervous at all
B:They were still young
C:They played naturally
D:They couldn’t have done better
在y3+1,3m+1,﹣x2y,abc﹣1,﹣8z,0中,整式的个数是( )
读课文《一句话》,根据意思写词语。
又急又响的雷,是云与地面之间发生的强烈雷电现象。____
若一个角的余角与这个角的补角之比是2:7,求这个角的邻补角.