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Hello! I am Amy. My friends all go to school with their schoolbags. And their schoolbags are heavy. What’s in their schoolbags? Tom has three storybooks and five maths books. Lucy has eleven pencils and two pens. Mike has five pens and eight notebooks. Lily has twelve picture books and one pencil box. I have seven erasers and two keys in my schoolbag. Are they heavy?
1．Tom is Amy’s friend.2．Amy has three storybooks and five maths books.
3．Mike has 5 pens and 8 notebooks.
4．My friends’ schoolbags are not heavy.
5．Lily has 20 picture books and 1 pencil box.
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
