处理熔体泵电流高时,应注意()。
A、避免粘度波动
B、及时提高终缩聚釜温度
C、熔体泵出口压力情况
D、终缩聚釜搅拌器扭距的变化
参考答案:C
— You play the piano so well. ______ do you have the piano lessons?
— Once a week. [ ]
A. How soon
B. How often
C. How long
D. How much
柑桔黄龙病的危害是什么?如何防治?