Which word best completes the sentence: It wasn't long ______ tea bags started to become popular in countries outside America?

• A. After
• B. Since
• C. Before
• D. While

Answer: (C)

The main idea tested is the use of a fixed phrase meaning “soon after.” Not long before is the natural way to say that something happened quickly after something else. Here, the sentence is saying that tea bags began to become popular in countries outside America not long after some prior event, so the best fit is before. The other options don’t form a natural time connection in this context: after would imply a different sequencing that doesn’t match the sentence structure, since the clause after “not long” would already be the event, and since or while don’t function as the usual temporal link in this idiom.