What is a 'storey'?
It's a level in a building.
What is a 'threat'?
Something that is a danger to something or someone
What does 'concern' mean?
To be worried about something
What does 'trek' mean?
To travel across an area of land that is sometimes rough like a MOUNTAIN, DESERT etc..
What does 'collapse' mean?
To fall down and become destroyed
