Cannon had . . . . . . . . unique qualities . . . . . . . . it was used widely in ancient times. A. that, that B. that, since C. such, so D. such, that

The correct answer is: C. such, so

The word “such” is used to introduce a list of qualities or characteristics. The word “so” is used to introduce a consequence or result. In this case, the sentence is saying that cannons had such unique qualities that they were used widely in ancient times.

The other options are incorrect because they do not make sense in the context of the sentence. Option A, “that, that,” is grammatically incorrect. Option B, “that, since,” does not make sense because there is no logical connection between the two clauses. Option D, “such, that,” is also incorrect because the word “that” is used twice in the same sentence.

Here is a more detailed explanation of each option:

• Option A, “that, that,” is grammatically incorrect. The word “that” is a subordinating conjunction that introduces a clause. In this case, the two clauses are “Cannons had such unique qualities” and “it was used widely in ancient times.” However, the word “that” cannot be used twice in the same sentence to introduce two different clauses.
• Option B, “that, since,” does not make sense because there is no logical connection between the two clauses. The first clause, “Cannons had such unique qualities,” is a statement of fact. The second clause, “it was used widely in ancient times,” is a statement of opinion. There is no logical reason why the fact that cannons had unique qualities would lead to the opinion that they were used widely in ancient times.
• Option C, “such, so,” is the correct answer. The word “such” is used to introduce a list of qualities or characteristics. The word “so” is used to introduce a consequence or result. In this case, the sentence is saying that cannons had such unique qualities that they were used widely in ancient times.
• Option D, “such, that,” is also incorrect because the word “that” is used twice in the same sentence. The word “that” is a subordinating conjunction that introduces a clause. In this case, the two clauses are “Cannons had such unique qualities” and “it was used widely in ancient times.” However, the word “that” cannot be used twice in the same sentence to introduce two different clauses.