What will you call your mother's brother's brother-in-law?

What is the riddle which can be asked all day with a different correct answer each time.

Find the missing letter in the last circle logically in the given below picture.

There is a circular car race track of 10km. There are two cars, Car A and Car B. And they are at the exact opposite end to each other. At Time T(0), Both cars move toward each other at a constant speed of 100 m/seconds. As we know both cars are at the same speed they will always be the exact opposite to each other.
Note, at the center, there is a bug which starts flying towards Car A at time T(0). When the bug reaches car B, it turns back and starts moving towards the car A. The speed of bug is 1m/second. After 5 hours all three stop moving.
What is the total distance covered by the bug?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Using the clues below, what four numbers am I thinking of?

The sum of all the numbers is 31.
One number is odd.
The highest number minus the lowest number is 7.
If you subtract the middle two numbers, it equals two.
There are no duplicate numbers.

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?