搜索
Mr. Smith is forgetful (健忘的). He always forgets his son’s birthday. This makes his son unhappy. Now he has a good idea. He gives some money to the shopkeeper (店主), and asks him to send some toys to his son on that day every year. His son is very happy to get the gifts on his birthday. One day, Mr. Smith gets home. His son tells him he receives (收到) some toys. Mr. Smith kisses his son and says, “Oh, a nice toy. But where did you get them?”
1．Mr Smith is forgetful.2．Mr Smith always forgets his son’s birthday.
3．Mr Smith asks the shopkeeper to send some toys to his son.
4．His son can’t receive a gift on his birthday.
5．Mr Smith knows where the toy is from.
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
