A:2 sin(x+ π4 )
B:2 sin(x﹣ π4 )
C:﹣ 2 sin(x+ π4 )
D:﹣ 2 sin(x﹣ π4 )
下列对细胞生命历程的叙述,错误的是( )
He works in a hospital. He is a ____.
下列有关金属的说法正确的是( )