（）。

A <img src="https://www.beizhujiaoyu.com/uploads/202208/161190921540771.png" width="132" height="118" />  B <img src="https://www.beizhujiaoyu.com/uploads/202208/161190922072751.png" width="130" height="119" />  C <img src="https://www.beizhujiaoyu.com/uploads/202208/161190922588531.png" width="132" height="119" />  D <img src="https://www.beizhujiaoyu.com/uploads/202208/161190923118241.png" width="132" height="119" /> 

A 0 B 1 C -1 D 1/2

A 1 B 0 C 2 D 1/2

A 5 B 3 C 3.5 D 1.5

A (0，0)是f(x)的极值点，但不是曲线y=f(x)的拐点 B (0，0)不是f(x)的极值点，但是曲线y=f(x)的拐点 C (0，0)是f(x)的极值点，也是曲线y=f(x)的拐点 D (0，0)不是f(x)的极值点，也不是曲线y=f(x)的拐点

A <img src="https://www.beizhujiaoyu.com/uploads/202208/161197389147851.png" width="91" height="34" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/161197389890041.png" width="110" height="34" /> C 0 D <img src="https://www.beizhujiaoyu.com/uploads/202208/161197390389111.png" width="186" height="34" />

A tcost-sint+C B tsint-cost+C C t(cost+sint)+C D tsint+C

A 2x⁴-4x²+2+C B 2(1-x²)²+C C -<img src="https://www.beizhujiaoyu.com/uploads/202208/161191004339351.png" width="20" height="52" />x⁴+x²+c D <img src="https://www.beizhujiaoyu.com/uploads/202208/161191005271841.png" width="20" height="52" />(1-x²)²+c

A 3π B 4π C 6π D 30π