腔肠动物的主要特征是：身体呈____对称；体表有 ____；有____无____。

已知f（x），g（x）都是定义在R上的函数，g（x）≠0，f′（x）g（x）＞f（x）g′（x），且f（x）=a^x•g（x）（a＞0，且a≠1），$\frac{f\left(1\right)}{g\left(1\right)}+\frac{f\left(-1\right)}{g\left(-1\right)}=\frac{5}{2}$，若数列$\left\{\frac{f\left(n\right)}{g\left(n\right)}\right\}$的前n项和大于62，则n的最小值为（　　）

    Betty is an American girl. She is thirteen. She is in Beijing with her parents. She doesn't know much Chinese. She can't speak Chinese well. Sometimes her friends don't understand her.

    It's Sunday morning. She is going to the zoo to see pandas. She is waiting at a bus stop. At the bus stop she asks a boy which bus to take to go to the zoo. But the boy can't understand her. Then she takes out a pen and a piece of paper. She draws a panda on it and shows the picture to the boy. The boy smiles and then shows her the way to the zoo.

如图，在Rt△ABC中，∠ABC=90°，DE是AC的垂直平分线，交AC于点D，交BC于点E，∠BAE=20°，则∠C的度数是（　　）

But you jump _______ high! （  ）