Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he quickly built his own device from an organ pipe and spectacle lenses.
Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he
Galileo had not invented the telescope, but when he heard, in 1609, of such an optical instrument having been made,
Galileo, even though he had not invented the telescope, on hearing, in 1609, that such an optical instrument had been made, he
Even though Galileo did not invent the telescope, on hearing, in 1609, that such an optical instrument had been made,
Even though Galileo did not invent the telescope, but when he heard, in 1609, of such an optical instrument being made, he
B and D - Incorrect because they do not include the "he" in the end. Without this subject, the rest of the sentence doesn't make much sense.
C - Incorrect because the primary clause is just a fragment:
* Remove the parenthetical phrases "even though...telescope", and "in 1609" and you will see that C is missing a verb as it reads: "Gallileo on hearing that such an optical instrument had been made, he quickly built his own"
E - Incorrect because of the double negative "Even though...but when he heard". Double negatives are a no-no on the test.
C, D, and E - Incorrect because "even though" is not appropriate in this case as it isn't consistent with the intended meaning of the sentence. "Even though" should be used to show mitigating circumstances, or to introduce a paradox as in the examples below:
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