用一句话概括下面这条新闻的要点（不超过25个字）。

    据英国广播公司报道，德国汉堡大学的天文学家在银河系中发现了一颗已有140亿年历史的恒星。它的形成能够追溯到宇宙形成的初期。这颗恒星被编为HE0107—5240。其罕见之处在于：与其它历史稍短的恒星不同，它完全是由宇宙大爆炸时产生的几种简单元素组成的，是迄今为止发现的第一颗不含金属元素的恒星。

    The mobile phone is a useful thing, but maybe I don't know ____ to use it. Sometimes it makes things difficult for me.

    One day I wanted to see my friend nearby. I could ____athis house in five minutes, but I thought it would be better to____him up. I rang him for the first time, ____ the line was busy.

    Five minutes later, there was an answer, but it was the wrongnumber. Then I tried ____ and this time I got an answer from him. I  ____ him if he was at home in the afternoon. And he said he would be at home all afternoon. So I went to his house, but then I found ____ in. I called him for the fourth time. This time I got   ____angry that I said, “You are not at home? But you just told me over the telephone that you would be at home all afternoon!”

    Here was his ____, “No, I said: I will NOT be at home all afternoon.”

    I went back to my room. What____could I do? Nothing!

（1）根据要求完成下列问题：

有以下物质：①SO₂Cl₂  ②C₂H₆  ③CS₂  ④HClO  ⑤H₂O₂含有非极性键的非极性分子是　 ____　；以极性键相结合，具有直线型结构的非极性分子是　 ____　；以极性键相结合，具有四面体形结构的极性分子是　 ____　；以极性键相结合，具有V型结构的极性分子是　 ____　；

（2）1994年度诺贝尔化学奖授予为研究臭氧作出特殊贡献的化学家．O₃能吸收有害紫外线，保护人类赖以生存的空间．O₃分子的结构如图5，呈V型，键角116.5℃．三个原子以一个O原子为中心，与另外两个O原子分别构成一个共价键；中间O原子提供2个电子，旁边两个O原子各提供1个电子，构成一个特殊的化学键﹣﹣三个O原子均等地享有这4个电子．请回答：

①臭氧与氧气的关系是 ____．

②下列与O₃分子的结构相似的是　 ____　．

A．H₃O⁺   B．CO₂   C．NO₂^﹣   D．BeCl₂

③分子中某原子上没有跟其他原子共用的价电子叫孤对电子，那么O₃分子有　 ____　对孤对电子．

④O₃分子是否为极性分子 ____（是或否）．