I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

What has one letter and starts with an E?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

What month of the year has 28 days?

How many letters are in the alphabet?

I make two people out of one. What am I?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

How many sides does a circle have?

The Puzzle: A girl, a boy, and a dog start walking down a road.

They start at the same time, from the same point, in the same direction.

The boy walks at 5 km/h, the girl at 6 km/h.

The dog runs from boy to girl and back again with a constant speed of 10 km/h. The dog does not slow down on the turn.
How far does the dog travel in 1 hour?