What runs around the whole yard without moving?

With pointed fangs I sit and wait; with piercing force I crunch out fate; grabbing victims, proclaiming might; physically joining with a single bite. What am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

John and his wife were living in a rural place. On a particular day, John's wife fell ill and he called the local doctor. When the doctor picked up, he said, "Doctor, my wife is ill. She might have appendicitis."

"This can't be possible! I took out her appendix two years ago myself," the doctor explained.

When diagnosed, John's wife was found to have appendicitis. How can this be possible?

Can you count the number of lines in the below picture?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

How many sides does a circle have?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

I always drive my customer away.

Who am I?

Which number should replace the question mark?