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An interesting hobby
Mr Brown has about 1,000 clocks in his house. He collects them from his childhood (童年). He puts these clocks everywhere: on the tables, sofas, in his old car, and even under his bed. His wife Mrs Brown doesn’t like those clocks at all. She has to clean all the clocks every minute. Even with so many clocks she can’t tell the right time.
1．There are 1,000 clocks and watches in Mr Brown’s house.2．Mr Brown started to collect clocks when he was a boy.
3．Mr Brown puts the clocks on the tables, sofas and in his old car, and even under his bed.
4．Mrs Brown likes collecting clocks, too.
5．Not all the clocks can tell the right time.
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
