代谢性酸中毒是
A.原发性HCO3ˉ减少B.继发性HCO3ˉ减少C.原发性H2CO3减少D.原发性H2CO3增多E.继发性H2CO3减少
参考答案:A
I_______ my homework at nine o’clock last Sunday morning.
A. am doing B. was doing C. do
出钢量到()时,加入合金及合成渣。
A.1/3
B.1/4
C.1/5
D.2/3