That's key to understanding planet formation.(这是理解行星形成的关键。)
Once, there was a little grey planet.(曾经，有一个小小的灰色星球。)
In reality, sea level varies according to the irregular interior of the planet.(事实上，海平面会根据地球不规则的内部而变化。)
It was way too faint to be a planet.(它太暗了，不可能是行星。)
We can't sit by and watch our planet destroyed.(我们不能坐视地球被破坏而不理。)
The next planet out, Uranus—after Saturn.(土星之后的下一颗行星是天王星。)
If there are so many stars out there, that means there might also be a planet just like the planet we live on.(如果那里有那么多星星，那就意味着可能也有一颗和我们居住的行星一样的行星。)
That means one out of six people on the planet uses Huawei hardware.(那意味着，地球上每六个人中，就有一个人使用华为的硬件。)
Saturn is the second biggest planet in the solar system.(土星是太阳系的第二大的行星。)
Extracting information about the large-scale composition of a planet from a sample weighing a millionth of a gram was a fascinating example of scientific endeavour.(从重量为百万分之一克的样品中提取有关行星宏观组成的信息是一个极为有趣的科学尝试实例。)
