—Does your mother like traveling by plane?            
—No, she thinks it is            expensive.                

—Have you found your watch ______?
—Yes, I have. I found it in my school bag ______.

Cathy did quite ______ in the English competitions, I did even ______.

There are           things each of us can do every day.              

—Have they finished the work?
—Not _______.

I think that eating much vegetables is         than eating much meat.              

根据括号中的要求改写下列句子。
1. He is going to Shanghai. (用现在完成时) ?
   ______________________________________
2. I heard about the news about the space travel. (改为同义句) ?
    ______________________________________
3. Scientists have found life on other planets.(改为否定句) ?
    ______________________________________
4. They haven't been to Mars. (用yet) ?
       ______________________________________
5. The spacecraft has reached the moon. (用just)?
    ______________________________________ 
6. Many astronauts have visited the space station. (用already) ?
    ______________________________________

—Excuse me, do I have to give back the book to you?
—No, if you haven't read it         .

—Hi, Tony. What are you            to?
—I've just watched a video.

           , it's difficult for tigers             in the wild.