She often has noodles breakfast. [ ]
A. for
B. on
C. with
D. at
答案：A
当地下水含氟( )mg/L时，长期饮用会破坏牙齿龈质而产生斑齿。
A．0.5
B．1.0
C．1.5
D．0.8
压滤机运行期间应检查与处理什么？
