根据句意和提示完成句子。
1. Has it reached ______ (火星) yet?
2. The journey has taken ______ (数月).
3. We haven't found life on other______ (行星) yet.
4. The sun and its planet are called ______ (太阳系).
5. It's an ______ (不载人的) mission.
6. The______ (宇航员) have discovered many interesting things ______.
7. The m______ (信息) has been around the country about three years.
