To answer this question, we need to analyze the quote and understand the tense and context used.
The quote states, "We would accomplish many more things if we _____ of them as impossible." This sentence is in the conditional tense, suggesting a hypothetical scenario.
Let's go through each option to understand why it is correct or incorrect:
Option A) would not think - This option is incorrect because it uses the conditional tense, which is appropriate for the sentence. However, it does not match the tense used in the quote, which is "did not think."
Option B) will not think - This option is incorrect because it uses the future tense, which is not consistent with the tense used in the quote.
Option C) had not thought - This option is incorrect because it uses the past perfect tense, which is not appropriate for the sentence. The quote implies a general statement rather than a specific past event.
Option D) did not think - This option is correct because it uses the simple past tense, which matches the tense used in the quote. The sentence in the quote suggests that if we do not think of things as impossible, we would accomplish more.
The correct answer is D) did not think. This option is correct because it matches the tense used in the quote and conveys the intended meaning.