为了保障消费安全，我们在消费过程中应该           （）                   
①购买商品或服务时索要发票            ②选择明星代言的产品
③不买“三无”产品                          ④看清商品生产日期、保质期、生产厂家、质量安全标志等 

    I am an apple. I'm a kind of sweet1You can find me grow in many places of the world, but I can't grow well in very hot places2 very cold places.

    I am not like my cousins 3and bananas. I am rounder than a pear and bananas are4than me. I am delicious,5people all over the world like to eat me. They can usually eat me6washing me. They can also cook me to 7all kinds of food, sometimes they put me in cans（罐头）to send me to other places of the world. Almost everyone can have 8 to buy me because I'm so cheap.

    I can also help people get9 There is a saying10English: An apple a day keeps the doctor away. Don't you think that I'm very great? I have many vitamins（维生素）inside, they are 11for you. I really wish to make you happy and healthy. so don't forget to 12me as often as possible（尽可能经常地）.

    But I also need your13, if you want to make me taste better, you must14 me well. Thank you for your love. I'll try to grow well and15sweeter. Then you will like to eat me a lot more.

有学者认为：“西周的封建社会，从纵剖面看，是一个宝塔式结构，王室之下，有几级的封建，从横切面来看，统治阶级中，也存在着以亲属血缘为基础的宗族组织”。这说明西周社会在政治上（    ）

内蒙古半干旱地区某学校的课外活动小组，为了研究不同厚度的积雪融化后对牧草生长量的影响，选了一块试验地。根据积雪厚度来设计，设计了同面积的两种样地和一个对照样地。样地A:积雪厚度30 cm；样地B:积雪厚度10 cm；对照样地:无积雪区(通过人工处理)。下面为一段时期的实验结果对比图。据此完成以下问题。