井口一级节流后到二级节流前管线的公称直径是多少（）。
A.DN100
B.DN150
C.DN200
D.DN250
参考答案：A
商业银行经营方针中作为条件的是安全性。()
In a given month, Friday is the 21st day of the month. What day of the week was the 5th of the month? （）
A.Monday
B.Thursday
C.Saturday
D.Wednesday
