两物体做匀速圆周运动，运动半径之比为4︰3，受到向心力之比为3︰4．则这两物体的动能之比为（  ）

已知一颗粒子等可能地落入如右图所示的四边形ABCD内的任意位置，如果通过大量的实验发现粒子落入△BCD内的频率稳定在$\frac{2}{5}$附近，那么点A和点C到时直线BD的距离之比约为（    ）

Mark: That's great! Anything interesting?

Tracy: Yes, working at an____park.

Mark: Wow, that sounds____ !

Tracy: So, have you found anything?

Mark: Nothing yet, but I have a ____ of leads. One is working as an intern for a record company-mostly answering phones. Or I can get a landscaping job again.

Tracy:____ an intern sounds more interesting than landscaping. You'd have better hours, and it's probably not as much work.

Mark: Yeah, but a landscaper earns more than an intern. And you get a great tan!

已知函数$\left(\omega >0\right)$$f\left(x\right)=3\sin (\omega x-\frac{\mathrm{\pi }}{6})(\omega >0)$和$g\left(x\right)=3\cos (2x+\phi )$的图象的对称中心完全相同，若$x\in 0,\frac{\mathrm{\pi }}{2}$，则$f\left(x\right)$的取值范围是                          （   ）

如图是“美丽乡村”建设中所倡导的一种生态农业模式图，请据图回答：