The weather affected the building of the Panama Canal quite negatively because the hot, humid weather made the work exhausting. The workers had to take long pauses until it was suitable for them to work again, because it was scorching hot in Panama so that no work could be done. This greatly slowed the process of building the Panama Canal because the workers didn't have the required conditions under which to work properly.
The US economic system is called a mixed economy because it includes not just private companies but also many government-run enterprises. Some of the latter enterprises are; the Export-Import Bank of US, Corp for Public Broadcasting, Federal Home Loan Banks and the Legal Services Corp for example.
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