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I have a beautiful schoolbag. It is made of cloth. It is black and purple. There are lots of things in my schoolbag. There is a red pencil-box, books and a water bottle. My schoolbag is always very heavy because I have many books. I have had my schoolbag for three years but it still looks very nice. I like it very much.
1．My schoolbag is black and white. （2．There are lots of things in my schoolbag. （
3．My schoolbag is always very heavy because I have many books. （
4．I have had my schoolbag for thirteen years. （
5．My schoolbag looks very old. （
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
