十万个为什么·科学启蒙30篇（3）

3 / 30

已读 0 / 30 课

银河系是什么

The Milky Way is our home galaxy—a vast, rotating disk of over 100 billion stars.
It looks like a hazy band of light across the night sky because we see it edge-on from inside.
Our Solar System sits about 27,000 light-years from the galaxy’s dense, star-packed center.
Most stars, including the Sun, orbit the galactic center once every 225–250 million years.
A supermassive black hole named Sagittarius A* lives at the very heart of the Milky Way.
Dark matter makes up about 90% of the galaxy’s total mass, though we cannot see it directly.
Spiral arms—like the Orion Arm where Earth resides—contain young stars and glowing gas clouds.
The Milky Way is slowly merging with the smaller Andromeda Galaxy, a process that will take billions of years.
Radio telescopes help map its structure by detecting invisible hydrogen gas emissions.
From outside, astronomers believe it would look like a bright white spiral with soft blue arms.

听 → 读 → 学表达 → 懂 → 今天会说这一句 → 跟读录音 → 自己说一句。

Radio telescopes help map its structure by detecting invisible hydrogen gas emissions. 射电望远镜通过探测不可见的氢气辐射来绘制其结构。
Our Solar System sits about 27,000 light-years from the galaxy’s dense, star-packed center. 我们的太阳系位于距银河系致密、恒星密集的中心约2.7万光年处。
Most stars, including the Sun, orbit the galactic center once every 225–250 million years. 包括太阳在内的大多数恒星，每2.25亿至2.5亿年绕银河中心公转一周。

这篇中文题目最接近哪一句？银河系是什么一次学校运动会的通知一份超市购物清单

课文第一句的意思更接近？银河系是我们的家园星系——一个拥有超过一千亿颗恒星的巨大旋转盘。今天学校放假了。请把窗户打开。

这一课主要在讲什么？（看英文标题） What Is the Milky Way? How to cook noodles A maths worksheet

Radio telescopes help map its structure by detecting invisible hydrogen gas emissions.

Radio telescopes help map its structure by detecting invisible hydrogen gas emissions.

第一版：录下来、回听、再听标准音。系统打分以后再加。

用今天的表达，自己说一句。

例子：Radio telescopes help map its structure by detecting invisible hydrogen gas emissions.