By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

There were two grandmothers and their two granddaughters.
There were two husbands and their two wives.
There were two fathers and their two daughters.
There were two mothers and their two sons.
There were two maidens and their two mothers.
There were two sisters and their two brothers.
Yet there are only six, who are buried here,
All are born legitimate and relationships clear.
How can this happen?

What is the word or phrase?

What goes up but never comes down?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

When monkey rotate the gear, which mark will be hit 1 or 2 ?

Why is Saturday stronger than Monday?

Which tank will fill first?

Can you place six X (crosses) in below board without making three in a row in any way ?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?