用括号中所给单词的适当形式完成下列句子.
1. Joanna received many _________ when graduating from middle school. (gift)
2. Alex is _________ years old and is taken good care of in the kindergarten. (fourth)
3. Whose school uniform is that on the chair, yours or _________? (my)
4. It was _________ for human begins to predict weather in the past. (difficulty)
5. There is a beautiful _________ on the wall in each room of my house. (paint)
6. You need to explain your opinions quite _________ when having a debate. (clear)
7. Let's hope that all our troubles will __________ soon. (appear)
8. The local people are ___________ that the whole nation are helping them rebuild the town. (thank)