在已学过的声母中,书写时只占中格的有____个 ,它们是____。
若实数x,y,z满足 x−2 +(y﹣4)2+|z+3|=0,则x+y+z=____.
函数fx=x3+x-3的实数解落在的区间是( )
— Were you at home _________?
— No, I was at school.