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Helen Keller was born in the 1. ______ in 1880. She had an 2. _______ at nineteen months old.
After that she couldn’t 3. ______ or 4. ______. But she 5. ______ to read, write and speak. It was difficult, but Helen was clever and she 6. ______ hard. Helen travelled 7. ______ the world and 8. ______ her story. She also wrote books and helped blind people. She was famous all 9. ______ the world. She is a 10. ______ for blind people, and also for you and me.
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
