Duck tape your eyes so you can’t see it
When the author said "the cause of America" is "the
cause of all mankind, he is refereeing o the worldwide plight of people under oppressive
government and all of those individuals are struggling against them, the
struggle for the cause of America is a symbolic statement for the struggle for
the cause of humanity worldwide wherever the same kind of circumstances are
found.
"He knew that the coldest snaps never froze these
springs, and he knew likewise their danger. They were traps. They
hid pools of water under the snow that might be three inches deep, or
three feet. "
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These lines above would often give the reader the specialized leans and the knowledge about the scientific subject.