Yes, Venus is<span> sometimes </span>called Earth's twin<span> because </span>Venus<span> and </span>Earth<span> are almost the same size, have about the same mass (they weigh about the same), and have a very similar composition (are made of the same material). They are also neighboring planets. However, </span>Venus<span> and </span>Earth<span> are also very different.
(just had to do a google search)</span>
Dry windy conditions. Mostly human causes. Also causes such as lightning and suns rays over smoldering debris piles.
I think it's the first one and the third one. Not completely sure though.
Yeah, it is the most widely accepted theory about the origin of Universe. If you are interested in it, I will suggest reading “A Brief History of Time”, by Stephen Hawking.
