What brain teasers are there?

What are the brain teaser questions as follows:

1. What kind of official cannot give orders but still has to smile to others all the time? Answer: Xinlang official.

2. A policeman ran away when he saw a thief. Why? Answer: He wanted to catch the thief quickly.

3. Xiaoming eats chewing gum every day, but others still say he has bad breath. Why? Answer: He swears every day.

4. Why can the frog jump higher than the tree? Answer: Because he jumps while standing on the tree.