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It's 1st February. The Blacks are cleaning their house because tomorrow is the Spring Festival. Look! Peter is carrying water with his brother Paul. Sam is cleaning the windows. Sally is sweeping the floor. Mr and Mrs Black are cleaning the kitchen. They will make delicious food for the family.
Two hours later, the house is nice and tidy.
1．Today is the Spring Festival.2．The Blacks are cleaning their house.
3．Sally is carrying water with his brother Paul.
4．Mr and Mrs Black are making delicious food for the family in the kitchen.
5．Two hours later, the house is nice and tidy.
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
