判定历史事件和历史事物的性质是研究和认识历史的重要方法，历史事件和历史事物的性质一般是由其阶级属性和社会属性决定的。我们认为十月革命是社会主义革命，最主要的论据是（    ）

下列关于我国民族区域自治制度的理解正确的是（  ）

如图所示是甲、乙两质点从同一地点运动的x﹣t图象，甲的是OA直线，乙的是OAC曲线，已知OA段曲线为抛物线，二者相交于A点，曲线OA在A点的切线AB交时间轴于t=2s处．则下列说法正确的是（   ）

阅读下列短文，从每小题的三个选项中选出最佳选项。

    Hello, I'm Ann. This is my family. There are five people in my family. My grandparents are old. They are teachers. My father is tall. He has a white shirt. He is a fireman. He is not afraid of fire. He can help people. He likes his job. My mother is tall and beautiful. She has long hair. She has a yellow skirt. She is a nurse. I don't have any aunts. What about you?

    In the second lesson, the teacher still____him to draw an egg, but he____the egg on a plate. Little Leo____unhappy and asked, "____do we draw eggs all the time?" "Look ____. It's an egg again, but it looks____." said the teacher.