THREE RIDDLES

1)
Two sisters there are,
One gives birth to the other,
And she in turn gives birth to the first.

2. What kind of train is often lost?

3. What do laughter, living well, and a good offense have in common?

Answers:

1. Day and Night
2. Train of thought
3. They are all the best. Laughter is the best medicine, living well is the best revenge, and a good offense is the best defense.