如图是位于水平桌面上的玩具“不倒翁”摆动过程的示意图，O点是“不倒翁”的重心．将“不倒翁”扳到位置1后释放，“不倒翁”向右摆动，经过竖直位置2到达另一侧最大摆角的位置3．关于这一现象，下列说法中正确的是（   ）

如图，矩形的长为6，宽为3，O为其对称中心，过点O任画一条直线，将矩 形分成两部分，则图中阴影部分的面积为（   ）

A: What are you going to do next Sunday?

B: I don't know. ____ ____ you?

A: I ____ to go to the zoo.

B: Good idea! What ____ do you like?

A: I like giraffes.

B: ____?

A: Because they're very friendly and cute.

B: ____ you want to see the giraffes first.

A: That's right.

B: What ____ animals do you like?

A: I like dolphins, ____.

B: Why?

A: Because they're ____ ____ interesting.

— All right. Come with me.