Who is your teacher?[ ]
A. Miss White.
B. She is tall.
C. He is in his office.
答案:A
已知f1(x)=sinx+cosx,fn+1(x)是fn(x)的导函数,即f2(x)=f1′(x),f3(x)=f2′(x),…,fn+1(x)=fn′(x),n∈N*,则f2011(x)=( )
A.sinx+cosx
B.sinx-cosx
C.-sinx+cosx
D.-sinx-cosx
酸碱的化学烧伤,急救首选()
A.酸性溶液冲洗
B.清水冲洗
C.碱性溶液冲洗
D.消毒剂冲洗
E.中和剂冲洗