What is the allusion for this? The rock was so heavy even Hercules would have a hard time moving it.

The allusion to the statement given was to show how heavy the rock was.

Allusion simply means a figure of speech that's used in calling something to mind without mentioning the thing explicitly.

The statement "The rock was so heavy even Hercules would have a hard time moving it" was to show how heavy the rock was without saying it directly.

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The rock is to heavy to be moved by a person (or maybe only one person).

Explanation:

faulty parallelism is a construction in which two or more parts of a sentence are equivalent in meaning but not grammatically similar in form.

the correct version of this faulty parallelism in the sentence is:

the hikers knew that the hike was six miles, that it usually required the entire day, and it would not be wise to start after 10: 00 a.m.

the problem is the last sentence, the first two have a basic subject+verb+object structure.

so, to give a proper balance to the structure, or better said, to give a parallel structure, we must write a basic s+v+o structure in all three sentences:

the hikers knew that the hike was six miles, that it usually required the entire day, and it would not be wise to start after 10: 00 a.m.

answer: metaphor: because there is a comparison between the treasures spread on the ground and the evil seed of adam drifting from the shoreline  

explanation: