The distribution of ancient fossils, Rock and mountain ranges, Climate zones
After Fidel Castro came to power in Cuba, he did two things that upset the United States immediately, he implemented the communist doctrine in the country, and he allied with the Soviet Union.
The implementation of communism in Cuba meant that everything that was private went into the possession of the government, including lot of companies that were owned by US citizens. That move was seen as robbery by the United States, as their citizens literary got their possessions confiscated without being paid anything.
The alliance with the Soviet Union upset and scared the United States. That move meant that their arch enemy will have influence over the island, and also probably make a military base just right of the coast of the United States, so that put them in a very bad tactical and strategic position.
Sad to say, the warning time that the residents of Sumatra had before the 2004 tsunami hit land was close from little to none. A rough estimation would around 15 - 30 minutes. They say that the primary cause would be that there wasn't any warning systems over the Indian Ocean at that time. Another thing, which is what most people who knew about it would point out as the real problem, is that there was no issuance of a warning in the first place. The quake was detected an hour or so before the tsunami occurred in the Pacific Tsunami Warning Centre located in Ewo, Hawaii. At that moment, the information was relayed to Australia and to the rest of the world. The question wasn't why the Centre didn't issue a warning, but why the whole world network of information didn't issue one. They say that other sophisticated data were available at that time and almost immediately since the tsunami was active.
Answer:
the answer is constructing a line perpendicular to a given line
I think it refers to worldwide mutual dependence between nations/countries as we depend on each other for the key things like food etc. on a worldwide level.