我国婚姻法规定“禁止近亲结婚”，其科学依据是（   ）

购买十种货物A₁，A₂，A₃，…，A₁₀，如果购买件数依次为1，3，4，5，6，7，8，9，10，11件，共需人民币1995元，如果购买件数依次为1，5，7，9，11，13，15，17，19，21件，共需人民币3000元，那么各购买一件共需人民币（　　）

大蒜中含有一种有效成分辣素“硫化丙烯”，其化学式为C₃H₆S，能杀菌，具有一定的抗病功能和食疗价值．请从硫化丙烯的化学式中获得的信息写出两条：

（1）____；

（2）____．

根据短文理解选择答案。

      It is Sunday today. Ann is shopping with her mother. She wants her mother to buy a sweater for her.

      In a clothes shop, she finds an orange one. She tries it on, but it's too small. She wants a bigger one, but the bigger ones are not orange. Ann doesn’t like other colours. Her mother asks, "Shall we go to another shop to have a look?" So they go out of this shop and go into another.

      The second shop is much bigger than the first, and in it there are many kinds of sweaters of different sizes and colours. Ann tries on an orange one. It's too big. She tries a smaller one. It's OK.

   “How much is it?” Ann’s mother asks the woman who sells clothes.

      Then they find it too expensive, and they don't have so much money with them.

    “Would you like a cheaper one?” The woman asks.

    “No, we shall take this one. My daughter likes it. We shall come back to buy tomorrow.” Ann's mother answers.

      After that, they leave the shop to buy some other things.

2010年第19届南非世界杯足球赛于6月1 1日在甲城市隆重开幕，读下图完成下列各题。