胎儿窘迫，血氧降低，首先出现的是下列哪种情况：
A．呼吸性酸中毒B．代谢性酸中毒C．呼吸性碱中毒D．代谢性碱中毒E．以上都不是
参考答案：A
It never me that he might be in trouble. [ ]
A. happened to
B. referred to
C. reflected to
D. occurred to
用丝绸摩擦过的玻璃棒带_________电荷，它与带负电荷的通草球靠近时，要相互__________。
