When was it built?

　　你在博物馆里看过恐龙展览吗？

　　on display意思为“陈列，展出”。这是一个介词短语，在句中可作表语和定语。同义词组是on show。如：

　　Some of her paintings are on display / on show in the local art galley.

　　她的一些画正在本地的美术馆展出。

　　The things on show / on display were all a hundred years ago.

　　展览的物品都有上百年的历史了。

　　5. There you can see the fossils of many kinds of dinosaurs.

　　在那里你能看到许多中恐龙的化石。

　　fossil意思为“化石”，是不可数名词；口语中还可指“守旧的人；落伍的人”。例如：

　　My grandpa doesn’t want to be an old fossil.

　　我爷爷可不愿做个落伍的人。

　　6. These eggs were found in the Gobi Desert by a group of scientists in the 1920s.

　　这些蛋是一群科学家于二十世纪二十年代在戈壁大沙漠发现的。

　　in the 1920s意思为“在二十世纪二十年代”。年代的表达法：在年份前加the，年份后加s。如：in the 1840s在十九世纪四十年代

　　7. So these eggs were laid long long ago by dinosaurs.

　　这些恐龙蛋是很久以前恐龙孵化的。

　　句中laid是动词lay（产卵）的过去分词。

　　— How many eggs does your hen lay every week?

　　— Her hen is laying well，about three every week..

　　— 你的母鸡每周产多少颗鸡蛋？

　　— 我的鸡正常下蛋，大约每周三个蛋。

　　注意区别以下几个动词，它们的原形，过去式，过去分词及现在分词。现将这三个词的四种形态列表如下：

           原形             现在分词       过去式           过去分词

           lay（摆放；产卵）laying        laid                laid

           lie（躺）    lying              lay                 lain

           lie（说谎）  lying              lied                lied

　　(1) It’s ten o’clock now. Don’t lie in bed all morning.

　　都十点钟了，别一上午都躺在床上。

　　(2) She is an honest girl. She won’t lie to me. She has never lied to me.

　　她是个诚实的姑娘。她不会说谎的。她对我从来都没撒过谎。

　　8. That means dinosaurs lived long before human beings appeared!

　　那就是说恐龙在人类出现之前就存在了。

　　appear不及物动词，意为“出现”，反义词是：disappear意思为“消失”。它们的名词形式分别是appearance和disappearance。如：

　　When we reached the top of the hill, the town appeared below us.

　　当我们到达山顶时，市镇就呈现在我们脚下。

　　Dinosaurs disappeared about 65 million years ago. Scientists try to explain their disappearance.

　　恐龙大约在六千五百万年前就消失了。科学家试着解释它们消失的原因。

　　9. I say it is special because the dinosaur was covered with feathers!

　　我说它特别，是因为恐龙身上长有羽毛。

　　be covered with在句中意为“被……覆盖”，有时还用be covered by。例如：

　　The road was covered with yellow leaves. The fields were covered by flood. The ground was covered with the white snow.

　　道路曾被黄叶盖住了。洪水曾淹没了田地。大地曾覆盖着白雪。

　　另外，cover… with…为主动形式，意思为“用……覆盖”。例如：

　　The beautiful girl often covers her face with her hands.

　　那美丽的姑娘经常用手捂着脸。

　　10. It was founded on October 1, 1949.

　　它是1949年报0月成立的。

　　found  vt.创立，创办，它与find的过去式和过去分词相同，注意在句中的区别。found的过去式和过去分词是在其后加-ed，即：

　　find（寻找）                   found             found

　　found（成立，建立）      founded          founded

　　例如：

　　Mr. Wang is going to found a new factory near our factory. He was very busy this morning. His lost coat was found under the bed at last.

　　王先生准备在我们工厂附近创办一家新工厂。今天早上他很忙，他丢失的上衣终于在床下找到了。

　　11. It’s interesting, isn’t it?

　　它有趣，是吗？

　　interesting和interested都来源于名词interest，interesting可作表语和定语，主语常指物；interested作表语，主语常指人，常构成be (become) interested in… 对……感兴趣。类似的词还有surprising和surprised。

　　surprising和surprised都是由surprise变换而来的，前者有主动含义，后者有被动含义，surprising的主语通常是物，而surprised的主语通常是人。Be surprised at + n. (v. + ing) 对……感到惊讶，be surprised后还可接不定式和that引导的从句。例如：

　　(1) The news from the girl is very surprising. She said that dull film was interesting.

　　从那个女孩那儿得来的消息非常令人吃惊。她说那个无聊的电影很有趣。

　　(2) The students were very interested in dinosaurs when they visited the museum. They were surprised at seeing th