选修3 UNIT 2 Out of this world 课时作业(1)-(2)（Word练习）-【创新方案】2024高考英语一轮复习一轮复习（新教材 新高考 牛津译林版）

UNIT2 课时作业（一）—（二） 课时作业(一)　主题阅读集群训练(限时40分钟) Ⅰ.阅读理解 A Scientists know quite a lot about stars.After centuries of pointing telescopes at the night sky, astronomers and amateurs alike can figure out key traits of any star, such as its mass or its composition. To calculate a star's mass, just look at the time it takes to orbit a companion star.Then do a bit of calculation.To determine what it's made of, look at the spectrum (光谱) of light the star sends out.But the one mystery scientists haven't quite cracked yet is stars' age. “The sun is the only star we know the age of，” says astronomer David Soderblom.He works at the Space Telescope Science Institute in Baltimore, Md.We use what we know about it and how it compares to others, he says, to figure out the age of other stars. Even well­studied stars surprise scientists every now and then.In 2019, the red supergiant Betelgeuse became gradually dark.At the time, astronomers weren't sure if this star was just going through a phase (位相)．The alternative idea was more exciting: It might be ready to explode as a supernova.(It turns out that it was just a phase.) The sun also shook them up when scientists noticed that it wasn't behaving like other middle­aged stars.It's not as magnetically active as other stars of its age and mass.That suggests astronomers still might not fully understand the timeline of middle age. Using physics and indirect measurement, scientists can make a rough estimate of a star's age.Some methods, it turns out, work better for different types of stars. Why do we even care? Galaxies are huge collection of stars of different ages.Stars' ages might help us figure out how such galaxies grow and evolve or how planets within them form.Knowing stars' ages might even assist in the search for life in other solar systems. 语篇解读：本文是一篇说明文。文章介绍了科学家们对恒星有了一定的了解。但是，目前科学家还没有完全破解关于恒星年龄的奥秘。 1．What does the underlined word “cracked” in Paragraph 2 probably mean? A．Covered.　　　　　 B．Described. C．Touched. D．Solved. 解析：选D　词义猜测题