Solve below rebus puzzle?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

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

What breaks yet never falls, and what falls yet never breaks?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

How many Watermelons are there in the below picture?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?