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Christmas is a very important Western festival. It is on the 25th of December. People decorate (装饰) their homes. They send Christmas cards to their relatives(亲戚) and friends, and they buy Christmas trees. They buy presents and put them under the Christmas tree. Some families open their presents on Christmas Eve. On Christmas Day, people can see lights in the street. They get together with their family and have a big meal. They also sing songs. They have a good time.
1．People send cards to their friends at Christmas.2．People put the presents in the Christmas tree.
3．On Christmas Eve, no one opens the present.
4．There are lights in the street at Christmas.
5．On Christmas Day, people have a big family meal and sing songs.
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
