2.Just as with the great navigators who first sailed around the Earth, gathering information about its size and curvature of the surface, astronomers have made new observations
The issue with 'with' aside, is E wrong because 'astronomers' is separated by 'gathering xxx'. The modifier should directly preceed the noun being modified?
NB, it's spelled "precede".
"Proceed" and "precede" are English words. "Procede" and "preceed" are not.
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As for question #2:
First, that's not really what "gathering xxxx" modifies. That's a comma -ing modifier; like others of that kind, it describes the previous
action.
I.e., it gives more detail about the navigators' sailing around the earth.
Second, sometimes there are two modifiers that both describe the same thing. Obviously, in those cases it's impossible to place
both modifiers directly after the noun. So they are just placed one after the other.
E.g., in OG Diagnostic #50, you have
a way of distributing xxxx on the internet that will yyyyy.If either of the two colored things appeared alone, without the other one, it'd be placed right after "a way". But they're both there, so one comes first and the other one comes second.