Question 37: Choose the best answer among A, B, C or D that best completes each sentence: …… the secret of how to make silk remain inside Asia, Europeans were forced to pay incredibly high sums of money for this mysterious material to be brought overland to Europe.
Answer D (as long as: as long as / until)
As long as the secret of how silk is made remains inside Asia, Europeans are forced to pay an extremely high amount of money for this mysterious material to be brought overland to Europe.
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