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问题 选择题
将椭圆x2+6y2-2x-12y-13=0按向量
a
平移，使中心与原点重合，则
a
的坐标是（　　）
A．（-1，1）B．（1，-1）C．（-1，-1）D．（1，1）
答案

椭圆方程x2+6y2-2x-12y-13=0变形为：（x-1）2+6（y-1）2=20，

则椭圆中心（1，1），即需按

a
=（-1，-1）平移，中心与原点重合．

故选C．

填空题

用句中划线部分词的反义词填空，使句意完整。

1. The bag is too heavy. You are not tall. You should carry the________ one.

2. His coat is________. His mother wants to buy him a new one.

3. He says, "English is very interesting, but maths is________."

4. My ruler is long. But his ruler is________.

5. His father is very old. But he likes to play with ________ people.

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问答题 简答题

我国“公民道德宣传日”是每年哪一天？
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