证明：∵ $AF\parallel BC$ ，

∴____ $=$ ____（理由是：____）

∵ $DE\parallel AC$ ，

∴____ $=$ ____（理由是：____）

∴ $\angle 1=\angle 2$ （理由是：____）

如图是甲、乙两种物质的熔化图象，由图象可知____ 种物质是晶体，该晶体的熔点是____ ℃

2016年6月长三角地区又迎来新一轮的国家战略机遇：《国务院关于长江三角洲城市群发展规划的批复》发布，长三角城市群发展规划正式获批。由江苏、浙江、上海、安徽四省市26个城市组成的新长三角城市群阵列，未来将打造改革新高地，推进金融、土地、产权交易等要素市场一体化建设，开展教育、医疗、社保等公共服务合作。

    长江三角洲城市群规划到2020年，基本形成经济充满活力、高端人才汇聚、创新能力跃升、空间利用集约高效的世界级城市群框架。到2030年，长三角城市群配置全球资源的枢纽作用更加凸显，服务全国、辐射亚太的门户地位更加巩固，在全球价值链和产业分工体系中的位置大幅跃升，国际竞争力和影响力显著增强，全面建成全球一流品质的世界级城市群。

    盐城既是环渤海经济区与长三角城市群对接发展的重要连接点，也是长三角北拓门户和产业梯度转移的先导基地，处于江苏沿海产业带的核心区位，是江苏沿海开发承南启北的战略支点，拥有对内对外的开放优势、接轨上海的区位优势、中韩合作的平台优势、特色鲜明的产业优势、绿色生态的宜居优势，成为苏北唯一入选的城市。

    加入长三角城市群的机遇属于盐城，但它决不会仅仅青睐盐城。对盐城来说，是机遇展露面前，挑战潜藏背后，考验也接踵而至。唯有行动和创举，才能乘势而上、借势双赢，推动盐城在新的起点上跨越发展、崛起腾飞。

阅读材料，探究下列问题：

    Lost cities that have been found

    The White City

    In 2015, a team of explorers to Honduras in search of “the Lost City of the Monkey God” led to the discovery of the White City. They found the ruins in the Mosquitia region of the Central American country — which is known for poisonous snakes, vicious jaguars and deadly insects. It is believed that local people hid here when the Spanish conquerors(征服者)occupied their homeland in the 16th century.

    Canopus and Heracleion

    Modern researchers were teased by the ancient writings about the Egyptian cities Canopus and Heracleion — where Queen Cleopatra often visited. But the cities weren't found until 1992, when a search in Alexandria waters found that the two cities had been flooded for centuries. Artifacts(史前器物)showed that the cities once highly developed as a trade network, which helped researchers piece together more about the last queen of Egypt.

Machu Picchu

    A Yale professor discovered “the Lost City in the Clouds” in 1911. A combination palaces, plazas, temples and homes, Machu Picchu displays the Inca Empire at the height of its rule. The city, which was abandoned in the 16th century for unknown reasons, was hidden by the local people from the Spanish conquerors for centuries, keeping it so well preserved.

Troy

    The ancient city of Troy in Homer's The Iliad was considered a fictional setting for his characters to run wild. But in 1871, explorations in northwestern Turkey exposed nine ancient cities layered(层叠)on top of each other, the earliest dating back to about 5,000 years before. It was later determined that the sixth or seventh layer contained the lost city of Troy and that it was actually destroyed by an earthquake, not a wooden horse.

    Most American families are smaller than the families in other countries. Children in the USA will leave their parents when they grow up. They usually live far from their parents because they want to find good jobs. They often write to their parents or telephone them. And they often go to visit their parents on holidays.

    Parents usually let their children choose their own jobs. Americans think it is important(重要的) for them to make decisions(作决定).

    Children are also asked to do some housework at home. And in many families，children will get money from their parents for doing some housework. Because American parents want to let their children learn how to make money for their own use.