Final answer:
The sixth paragraph in the passage develops claims by describing a nonmilitary use for submarines and supporting the notion that submarines are a great invention. Other options provided about recreation and scientific impact, or air storage, are not referenced in the given context.
Step-by-step explanation:
The sixth paragraph serves to develop claims within the passage by providing details that support the overall thesis or central ideas. Specifically, it contributes in two main ways:
- It describes a nonmilitary use for submarines, illustrating the versatility of submarines beyond their traditional role in warfare. By highlighting how submarines can have civilian applications such as in science or recreation, the paragraph broadens the understanding of the reader regarding the scope of submarine usage.
- It supports the title by giving an example of a great invention. The paragraph lends weight to the claim that submarines are an impressive technological achievement by showcasing their adaptability and utility in various fields.
The other options listed, like illustrating how submarines can be used for recreation and explaining the effects of submarines on science, are related but not explicitly mentioned in the sixth paragraph as available to us. Similarly, while the storage of air in submarines is a critical feature, it is not discussed in the context given.
Therefore, based on the information provided, the two correct options are that the sixth paragraph describes a nonmilitary use for submarines, and it supports the title by giving an example of a great invention.