改写句子 按括号中的要求完成句子，每个空格填一个单词。
(1)There is a big lake in the park.  (改为否定句)
There____  ____ a big lake in the park.
(2)He has lived in this village for 80 years. (就句子画线部分提问)
____ ____ he lived for 80 years.?
(3)The problem is very difficult. I can't work it out.  (改写句子,句意不变)
The problem is ____ difficult for me ____ work out.
(4)"What are you doing ?"My mother asked me. (改写句子,句意不变)
My mother asked me____ I ____  doing .
(5)We shouldn't drop litter anywhere when we visit the interesting places. (改写句子,句意不变)
Litter shouldn't____   ____    anywhere when we visit the interesting places.