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When the summer holiday comes, the weather is usually very hot. Some children prefer to go swimming in the open water in groups. Parents are quite worried. It’s very important to make sure that the children won’t forget the safety tips. “It’s not safe to swim in the lake. You can swim in a swimming pool. ”parents often say to their children.
Here are some tips also for swimming safety. First, tell your parents before you go to swim. Second, you can’t swim when you are too full. Third, do some exercise before you go into the pool. Fourth, don’t swim for more than two hours each time. Fifth, if your friend is in danger, don’t try to help him or her by yourself. Do ask adults for help.
1．The underlined phrase “the open water” means the swimming pool.2．Children need to tell their parents before they go swimming.
3．Don’t eat too much before you swim.
4．You can swim for 1 hour each time.
5．If your friend is in danger, you can help him or her by yourself.
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
