The Continents were all joined into one land mass
Arch bridges have a semicirclar, curved support.
It allows power boats to have stability while cruising. The cathedral hull is like a trimaran in terehat it has one main and two side hulls stuck together so that has a somewhat square to rectangular shape and therefore exhibits greater stability than a single hulled boat. It became more popular with the advent of fibreglass boats in the 1960's and '70s.
A general rule for adding text to a slide is to use not more than two fonts in a presentation and vary the font size. Besides adding text you can also import text, photographs, numerical data, and facts from files created in programs such as Microsoft word, excel and access.
