They drained the water.

For building across a river you could wait until a dry season to build your bridge when the water level would be low or you could sink logs into the ground to make a sort of dam around your construction site which you could then drain(either using pumps or just buckets depending on technology) then you build your support pillar before breaking down the dam you built.

Mostly, it involved building in the safest and easiest place instead of the most convenient for travel.

IQ is neither objective nor static.

You can certainly increase your IQ(which is determined by test results for reasoning and problem solving) by studying and practicing those skills.

Additionally, numerous studies have shown that the modern IQ test heavily skews towards "western" and wealthy individuals with education provided within a Prussian style school system(like most western countries provide).

Your question is asked under a false premise.

1. Most high level execs receive their bonus in the form of stock option. A stock option is the option to purchase a stock at a price that is set(usually below current market at the time the option is awarded). They can exercise these options at any time because the price is set before they receive them and it is part of their compensation.
2. When an exec(or some other person who has valuable insider information) wants to transact(buy or sell) on the stock they have insider info for they are generally required to announce their intention and the price at which they are selling several weeks in advance. There are also "black out dates" where they are not allowed to buy or sell, such as around earnings announcements(since earnings are a regular event that often has a big impact of stock price).

>for €54 with my (British) debit card and was given the option to pay seemingly less in £ instead (£50). (£50 is roughly €57!).

Math is hard, eh?

If you are feeling a sensation that isn't actually there you should definitely consult a medical professional.

Dallas has 7 suburbs that are larger than Killeen.

I stand corrected, I stand by Kileen being rural though.

Name a major (US) military base that isn't in a rural area.

It's too expensive to put bases in urban or even suburban areas.

It's rural Texas so I'm honestly a little surprised this was an issue.

Humans also like being special so we move the goal post when animals take steps towards diminishing our "specialness."