合并同类项:①15x+4x﹣10x=( );②﹣p2﹣p2﹣p2( )
9x;﹣3p2
阅读下列语句:
①对顶角相等;②同位角相等;③画∠AOB的平分线OC;④这个角等于30°吗?在这些语句中,属于真命题的是_____ _____(填写序号)
The meeting will begin soon. Please get ready ________ it.[ ]
A. to
B. for
C. about
D. with