搜索
There are some extreme sports（极限运动）in the world. People must have some skills（技能）to p1． extreme sports because most of them are very d2． . And they n3． some special equipment（器材，装备）for safety（安全）.
Bungee jumping（蹦极）is a kind of extreme sports. People jump f4． a high tower with some special l5． ropes. They need the ropes f6． their safety. Rock climbing also needs some long ropes for sport p7．. Those ropes are different from the o8． we use in our daily life. One easier extreme sport is skateboarding. You need a s9． and a helmet. Young people like to play it outdoors. Some of the players can do a lot of difficult movements（动作）on the b10． .
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
