——Would you mind my opening the window?——___________ It's much too hot here.
A:Certainly.
B:Of course not.
C:All right.
D:Yes, you can.
____
—We will ____ a short play.
关于函数f(x)=2(sinx-cosx)cosx的四个结论:P1:最大值为2; P2:最小正周期为π;P3:单调递增区间为kπ-π8,kπ+38π,k∈Z;P4:图象的对称中心为k2π+π8,-1,k∈Z .其中正确的有( )