People can fall: â  from the edge of a completed roof; â  from the edge where work is being carried out; or â  through openings or gaps. Edge protection Unless the roof parapet provides equivalent safety, temporary edge protection will be required during most work on flat roofs.
Why is astronomy considered the original science? Astronomy is the oldest science for our ancients either drew or made structures according to seasons or movements of celestial bodies in our Universe.
1 Science is very important just like math. 2  Science is used everyday by people. 3  Science can be considered a series of trials and errors. 4  By our trials and errors we make new inventions.