They have been practicing the guitar for two hours.(改为同义句)They have been practicing the guitar _____ two hours_____.

问题描述:

They have been practicing the guitar for two hours.(改为同义句)
They have been practicing the guitar _____ two hours_____.

since
ago

They have been practicing the guitar for two hours.(改为同义句)
They have been practicing the guitar _since____ two hours__ago___.
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