某产品的三个质量指标分别为x，y，z，用综合指标S=x+y+z评价该产品的等级．若S≤4，则该产品为一等品．现从一批该产品中，随机抽取10件产品作为样本，其质量指标列表如下：

（Ⅰ）利用上表提供的样本数据估计该批产品的一等品率；

（Ⅱ）在该样品的一等品中，随机抽取2件产品，

（i）用产品编号列出所有可能的结果；

（ii）设事件B为“在取出的2件产品中，每件产品的综合指标S都等于4”，求事件B发生的概率．

My parents

    My parents work in a show factory. They get up at five thirty. They first get breakfast ready. Then they go to work by bus. They work there from eight to five. They come home at about six and prepare supper for us. Mother washes clothes in the evening. Father often makes toys for us. They are busy all day.

仔细阅读，判断句子正误。

人体皮肤下面的一条条“青筋”是下列哪种血管（  ）

南回归线位于（   ）