What happened when the wheel was invented?

In the following picture, E is going to slide the object down and as per the terrain and the physics, the round object is going to travel all the way till the end. Now, can you analyze who all people will die when it happens?

Using eight eights and addition only, can you make 1000?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

What can go up a chimney down, but can’t go down a chimney up?

What building has the most stories?

It is always ahead of me yet I can never see it. What is it?

What has many teeth, but cannot bite?

The following sentence is false. The preceding sentence is true.
Are these two sentences true or false?

I am quite hot but become too cold if you remove the first two letters. What am I?