Question

【题目】They have sold a large number of air-conditioners since the temperature is high. (改为被动语态)
A large number of air-conditioners have since the temperature is high.

Answer 1

【答案】been；sold
【解析】句意：因为温度这么高，他们已经卖了大量的空调。本题要求改为被动语态，原句have sold是现在完成时态，变被动语态的时候，不能改变时态，现在完成时态的被动语态是have been +动词的过去分词，空前有了have，所以答案是been sold。