采用两级压缩制冷系统是为了()。
A、制取更低的温度
B、减少压缩机功耗
C、提高制冷系数
D、降低制冷设备成本
参考答案:A
With _____she needed . she left the market-place.
A.something; to buy
B.anything; having bought
C.everything; buying
D.everything; bought
釉的膨胀系数大于坯较多时,易产生裂釉。