—Alice, why didn’t you come yesterday?
—I ______, but I had an unexpected visitor.
A:had
B:would
C:was going to
D:did
下列实验现象的描述符合事实的是 ( )
已知ω>0,函数fx=cosωx+π4在π2,π上单调递增,则ω的取值范围是( )