给我10个英文单词，它们都有以“im-”为前缀的相反词。

1. possible - impossible
2. perfect - imperfect
3. patient - impatient
4. proper - improper
5. practical - impractical
6. mature - immature
7. mobile - immobile
8. mortal - immortal
9. material - immaterial
10. moral - immoral