CO轻度中毒的症状有:轻度的头痛、头晕、眼睛发花、全身无力,在劳动时感到呼吸有些急迫短促。()
参考答案:对
—He has _______his dictionary. Have you seen it?
—Yes, of course. I _______ it on your desk just now. [ ]
A. lose; saw
B. lost; have seen
C. lose; have seen
D. lost; saw
奶牛产奶性状主要有()、()的含量确定。