Bill and Ben are shopping.
Bill: There is a store. Let's go in.
Ben: Let's go.
Assistant: Can I help you?
Bill: Yes, do you have any shoes?
Assistant: Yes, we do. What size do you want?
Bill: Size 21, please.
Assistant: Here you are.
Bill: Oh, this shoe is just right for my left foot. But this one is too big for my right foot.
Assistant: You can try this pair on. They are size 20.
Bill: Oh, this time my right foot is all right. But this shoe is too small for my left foot.
Assistant: What size do you want?
Bill: I don't know. Can you give me an idea?
(1)Bill wants to buy a pair of shoes.
(2)The shoes are too small.
(3)The shoes are too big.
(4)Bill's left foot is big. His right foot is small.
(5)What size will Bill buy? Can you give him an idea?
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