1. (2006 College Entrance Examination Mathematics (Shandong Science) Question) Given the odd function $f(x)$ defined on $\mathbf{R}$ satisfies $f(x+2$ ) $=-f(x)$, then the value of $f(6)$ is
A. -1
B. 0
C. 1
D. 2
1. B  From $f(x+2)=-f(x)$, we can deduce that the function $f(x)$ is a periodic function with a period of 4. Since $f(x)$ is an odd function defined on $\mathbf{R}$, we have $f(6)=f(2)=f(-2)=-f(2)=0$, hence the answer is B.