国产光学瓦斯检测器，将光谱第一条黑纹对在“0”上，则第五条条纹应在（）数值上
A、3%
B、5%
C、7%
参考答案：C
Rose feels lonely from time to time because all her friends____________.
A．married
B．have married to
C．have got married
D．marry
国产塔底油裂化的催化裂化催化剂有哪些？
