最新九师联盟2024届高三英语试题
最新九师联盟2024届高三英语试题
高考的科目有英语、语文、数学、文综、理综等，是一次很好检验考生高三学生复习成果的考试，本期小编为大家整理了高考各科试题及答案解析，包括英语答案及试卷、语文答案及试卷、数学答案及试卷等。
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Ancient builders across the world created structures that are still standing today, thousands of years later. Roman builders built thick concrete sea barriers against waves. Mayan builders created great sculptures, and Chinese builders constructed walls against foreign enemies.
A growing number of scientists have been studying materials since a long time ago. They are breaking apart pieces of buildings and reading historical texts hoping to learn how they have stood for thousands of years. The research has turned up a surprising list of materials that were mixed into old buildings. They include tree bark, volcanic ash, rice and beer. These unexpected materials cam have the ability to get stronger over time. Figuring out how to copy these features can have real impacts today. While some of our modern concrete has the strength to hold up very tall buildings and heavy structures, it cannot compete with the durability of these ancient materials.
Many scientists have turned to the Romans. Starting around 200 BC, the Roman Empire was building concrete structures that have stood the test of time. Even in places where seawater has been hitting structures for ages, you will find concrete basically the way it was when it was poured 2,000 years ago. They think they have found an important reason why some Roman concrete has held up structures for thousands of years. That the ancient materials have an unusual power to restore themselves when they form is the most shocking for them. Exactly how is not yet clear, but scientists are starting to find the reasons.
Today’s builders cannot just copy the ancient processes. Even though Roman concrete survived from earlier times, it couldn’t hold up heavy buildings. Instead, researchers are trying to take some of the ancient materials and add them into modern mixes. People don’t need to make things last quite as long as the Romans did. If we add 50 or 100 years to concrete’s lifespan, we’ll surely require less pulling down, less maintenance and less material in the long run.
最新九师联盟2024届高三英语试题