Read the original and improved research questions.
original: what is the relationship between natural resources and the industrial revolution?
improved: how did coal contribute to the industrial revolution in pittsburgh in the 1880s?
which of the basic question words improve this research question? select three options.
how
what
when
where
why

The primary question words that had assisted in enhancing the given research question would be:

A). How

B). What

C). When

The question word 'how' has helped improve the significance of the research question as it will exemplify the way in which natural resources played a crucial role in the Industrial revolution. While the question of 'what' will narrate the incident of Pittsburgh to which the readers can relate and believe the efficacy of the claim. The question 'when' would further demonstrate and substantiate the validity of the author's claim that during the late 19th century these resources had an influential play and improve its clarity and reliability.

Hence, options A, B, and C are the correct answers.

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What, how, when

Be specific and stick to a topic.  Know your source and understand how something came to pass or work.  It is always important when doing research to understand when something occurred so you can accurately complete your research.

Explanation:

The advantage of banking with national retail banks is that they charge fees for many services.

Independent executive agencies are more specialised.