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I’m Tom. I’m an American boy. I’m twelve. I have got a Chinese pen friend. His name is Li Yang. I have got some postcards from Li Yang. I know there are lots of beautiful places in China. The Changjiang River is the longest river in China. The West Lake is in Hangzhou. The Huangshan Mountain is in Anhui. China is very beautiful. I want to visit it next year.
1．Tom has got a friend in England.2．Li Yang sends some postcards to Tom.
3．The longest river in China is the Changjiang River.
4．The Huangshan Mountain is in Anhui.
同类型试题
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
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
