呼吸性酸中毒合并代谢性碱中毒的血气改变有()
A.pH下降
B.HCO3-减少
C.血钾降低
D.血氯降低
E.二氧化碳分压下降
参考答案:C, D
There are many kinds of synthetic materials, ______ plastics are the most common.
A.between which
B.of which
C.in which
D.among which
自然引风式扩散燃烧有()个特点。
A.四
B.五
C.六
D.七