( )(1)The bird is flying.
![](http://static.xuejinqu.com/qimg/68a/68a15484bfc1cc2ae587896cdb917c0c.png)
( )(2)We are looking at some ducks.
![](http://static.xuejinqu.com/qimg/68a/68a15484bfc1cc2ae587896cdb917c0c.png)
( )(3)The sun is shining.
![](http://static.xuejinqu.com/qimg/68a/68a15484bfc1cc2ae587896cdb917c0c.png)
( )(4)The birds are singing in the tree.
![](http://static.xuejinqu.com/qimg/68a/68a15484bfc1cc2ae587896cdb917c0c.png)
( )(5)It’s raining.
![](http://static.xuejinqu.com/qimg/68a/68a15484bfc1cc2ae587896cdb917c0c.png)
( )(6)There are some sandwiches.
![](http://static.xuejinqu.com/qimg/68a/68a15484bfc1cc2ae587896cdb917c0c.png)
![](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)