在地理科学上，沧海桑田的含义是（   ）

中国的养老方式是“反哺式”，而西方则是“接力式”。这说明 （  ）

图1为“某区域示意图”．读图完成下列各题．

根据短文内容，从A、B、C、D四个选项中选择正确答案填空。

    Children often  1 this game. They play it like this: Six 2 stand in a row(排) 3 the class. They put their hands 4 their backs(背), so you can't see their hands. The teacher gives one of them 5 rubber. The rubber goes 6 one student to another -- first one way, then the other. They must keep their hands behind their backs. The other students in the class keep their eyes    7. They can't look.

    Then the teacher says: “Stop and put your hands  8 you now.” Now the other students 9 their eyes, and guess who has the rubber. They ask questions like: “Li Lei, is it in  10 right hand?” They can have only five guesses.

已知函数f(x)为奇函数，且当x＞0时，$f\left(x\right)=x^2+\frac{1}{x}$，则f(－1)＝（   ）