( ) 1.
![](http://static.xuejinqu.com/qimg/a2e/a2e25dcbad2b21c8f6af6d3f9c292816.png)
— How old is Guoguo?
— She’s nine years old.
( ) 2.
![](http://static.xuejinqu.com/qimg/cf5/cf518a91684183e1818bd3796e2e3793.png)
— How old is Bill?
— He's seven years old.
( ) 3.
![](http://static.xuejinqu.com/qimg/07a/07a5cf81b04273f6bc5d4aef0eeaf639.png)
— How old is Tom?
— He's ten years old.
![](http://static.xuejinqu.com/images/y-prise.png)
同类型试题
![](http://static.xuejinqu.com/images/medal.png)
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
![](http://static.xuejinqu.com/images/avatar.png)
![](http://static.xuejinqu.com/images/avatar.png)
y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2
![](http://static.xuejinqu.com/images/avatar.png)
![](http://static.xuejinqu.com/images/avatar.png)