用括号所给单词的适当形式填空。

1. I take my dog out for a walk _______(one) a day.

2. There's somebody _______(hide) behind the door.

3. Sandy does her homework _______(careful) than Tom.

4. There are many tall _______ on both sides of the street. (build)

5. Why does she look _______ today? What's the matter? (worry)

6. He is old enough. He can do it by _______. (he)

7. It's great _______ to play with my pet. (funny)

8. Please write a short passage about your dog at _______ 100 words. (little)

9. Many _______ come to visit the Great Wall every year. (visit)

10. Don't climb over the wall. Look! It says, "It's _______" (safe)