What do the following words have in common?

1. BE

2. FRAY
3. DIVE
4. ACCENT
5. PRESENT

HINT:
The same two, consecutive letters, in the same order, will change each word to a new one.

Answer:

The letters ID can be inserted into each word to get a new one:

1. BIDE
2. FRIDAY
3. DIVIDE
4. ACCIDENT
5. PRESIDENT