1.(单选题，4.3分) 摆线{}x=a(t-sin t)y=a(1-cos t)dt

1.(单选题，4.3分) 摆线$\left\{\begin{matrix}x=a(t-\sin t)\\y=a(1-\cos t)\end{matrix}\right.$的一拱与x轴所围的平面图形绕x轴旋转所得旋转体的体积$V_{x}=$

A. $\int_{0}^{2\pi a}\pi a^{2}(1-\cos t)^{2}d[a(t-\sin t)]$

B. $\int_{0}^{2\pi}\pi a^{2}(1-\cos t)^{2}d[a(t-\sin t)]$

C. $\int_{0}^{2\pi a}\pi a^{2}(1-\cos t)^{2}dt$

D. $\int_{0}^{2\pi}\pi a^{2}(1-\cos t)^{2}dt$