下列产品单位耗能<标准煤)最低的是( )。
A．每千瓦小时火电供电煤耗
B．每吨钢综合能耗
C．每吨铝综合能耗
D．每吨铜综合能耗
参考答案：A
— It's eight o'clock already. Jack _____ be here by now.
— Oh, he told me that he was going to see his dentist and wouldn't be back until ten. [ ]
A. must
B. can
C. should
D. need
POY条干数值高，以下说法正确的是（）。
A、POY轴向粗细均匀性好
B、对应后加工产品的染色均匀性可能较差
C、可能是由于纺丝上油均匀性差所致
D、条干属于企业内控指标，因此不必对条干高的产品进行降等处理
