题目内容：

阅读下面的短文，根据文中信息完成文后表格。（每空一词）

Scientists think that there has been life on the Earth for hundreds of millions of years.

However, we have not found life on any other planet yet.

The Earth is a planet and it goes around the Sun. Seven other planets also go around the Sun. None of them has an environment like that of the Earth, so scientists think there may be no life on them. The Sun and its planets are called the solar system (太阳系), and our solar system is a small part of a much larger group of stars and planets, called the Galaxy or the Milky Way. There are many, many stars in the Galaxy, and our Sun is only one of them.

Scientists have also discovered many other galaxies in the universe (宇宙). They are very

far away and their light has to travel for many years to reach us. So how large is the universe? It is impossible to imagine.

Scientists have sent spaceships to the planet Mars to take photos. They have even sent spaceships to travel outside the solar system. However, no spaceship has travelled far enough to reach other stars in our Galaxy.

Scientists have always asked the questions: with so many stars in the universe, are we alone, or is there life out there in space? Have there been visitors to the Earth from other planets? Why has no one communicated with us? We do not know the answers yet.

Planets in our solar system	There are1.planets going around the Sun in our solar system.
Life on the planet	No life has been found on other planets2.the Earth in the solar system because they have a3.environment from that on the Earth.
The solar system	It is a small part of the Galaxy and the4.is only one star in it.
Galaxies	Besides our galaxy, many other galaxies in the universe have been 5..But they are very far away from us and it6. many years for their light to reach us.
The universe	It is7.large to imagine.
Spaceships	Spaceships have been sent to take photos of the planet 8.and outside the solar system.But other stars in our Galaxy are so far that no spaceships can9.to them.
Questions	There are many questions about the universe and life in space,but no one can10.them yet.