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Dear Amy,
I know you collect stamps, so I'm sending you some English stamps. I hope you will like them. Did you know that the first stamp in the world appeared（出现）in England? It was in 1840. The stamp's name was "Penny Black". I didn't buy you a Penny Black because it is very expensive now.
Write soon.
Grandma1．Amy collects stamps. （
2．The first stamp in the world appeared in 1804. （
3．The first stamp was called “Penny Black”. （
4．The Penny Black stamps are very cheap. （
5．Grandma bought Amy a Penny Black stamp. （
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
