A:which
B:why
C:that
D:how
实验室常用下列装置来制取氧气:
2.5,﹣2,|﹣4|,﹣(﹣1),0,﹣(+3)
About of the workers in the factory were born in the .
某网站上为纪念“百日维新”115周年而展开了大讨论,下面观点不正确的是( )
已知函数f(x)对任意x∈R都有fx+4-fx=2f2,若y=fx-1的图象关于直线x=1对称,且f(1)=2,则f(2011)=( )