根据汉语提示填写单词    

1. Please speak _________(轻声). The baby is sleeping.    

2. I seldom go to town because it's too _________(吵杂).    

3. She can _________(表达)herself in good clear English. 

4. There is a _________(非常小的)country in Europe. There are only a few policemen in it.    

5. When you write a poem about nature, you have to write different ________(景色).

求函数y=lg（4-x²）的单调递增区间为______．