In Pontevedra, a city in Spain, people don't shout. Since cars are banned (明令禁止) in the city, there are no noises from cars. People don't have to try hard to make themselves heard. What you hear in the street, instead, is the singing of birds.
Miguel Lores, the mayor (市长), opens the windows of his office, and the sound of human voices
Lores became mayor in 1999. He spent months
At first, Lores thought of improving traffic conditions. However, he couldn't come up with a good plan. After lots of discussions, the government finally decided
The change

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

