I will have a holiday next week and I can't decide what to do. I have a lot of work to do 1 and this would be a good chance 2. But I don't like 3 the holiday in such a way.I can work at home all the rest of the year.

    Last year I went 4 to the mountains. 5 there was beautiful， but it is too cold this time of a year. And it's really6 far to go for a short holiday. I decide 7 this isn't a good time to8the mountains.But I9to go somewhere else.Perhaps this would be a good chance to go to the beach（海滨）.I like to go for walks10the seashore 11the warm sunshine and watch the water. It's only eight miles away and I could get there 12about two hours. After thinking it13，I am sure that this is a 14time for the seashore than15.

    Oh， here is a 16from Jim. He 17 he is going to his house in the mountains for the18，and he19me to go with him.20 giving it some more thought， I wrote back to Jim and thanked him for that.

①烧碱     ②纯碱     ③金属钠     ④氯气    ⑤盐酸．

问题一：偶然与必然

有人认为，哥伦布是因为“迷路了”，才偶然“发现”了美洲。也有人认为，当时即使没有哥伦布，也必然会有别人“发现”美洲。

据材料并结合所学知识，谈谈你的观点并说明理由。

问题二：发现与相遇：15、16世纪以来人们通常使用“哥伦布发现美洲”的提法，“发现”的意思是“使所有人和所有民族都并入欧洲文明”。1984年，部分拉美学者倡议改称“美洲发现——两个文明汇合”。1992年，联合国教科文组织主张以“两个大陆相遇500年”为主题，举行哥伦布航抵美洲纪念活动。

问题：

If we ________ something, we express something fully and clearly.

一个几何体的三视图如右图所示，这个几何体是（  ）．