Question

people began streaming songs online.
the music industry changed dramatically.
although so that once ← joining words
① combine the sentences into one sentence. use one of the joining words.
type your answer here.

Explanation:

We need to combine the two sentences using one of the given joining words. Let's analyze each joining word:

• "although" is used to show contrast, but the two sentences have a cause - effect or sequential relationship rather than a contrast.
• "so that" is used to show purpose, which doesn't fit here as the first event (streaming songs online) led to the second event (music industry change), not a purpose.
• "once" is used to indicate that after a certain event (people began streaming songs online) happened, another event (music industry changed dramatically) followed. So we can use "once" to combine the sentences.

Answer:

Once people began streaming songs online, the music industry changed dramatically.