—Yes, but I only wish ________ music now.
A:listen
B:listen to
C:to listen
D:to listen to
某兴趣小组为测定实验室中一瓶久置的过氧化氢溶液中溶质的质量分数,实验测得相关数据如下图所示:
已知点P(﹣2,3)关于原点的对称点为M(a,b),则a+b=____ .