A:were
B:was
C:are
D:is
— Shall I book some seats for the concert?
—______. I've done that.
一组数据1,x,4,y,5的中位数和平均数都是3(x<y),则x=____.这组数据的方差是____.
若cos2αsinκ-π4=-22,则cosα+sinα的值为( )