如果显示仪表指示不稳定或不符合流量变化规律，可检查（）
A、重新进行标定
B、电磁干扰情况
C、仪表常数
D、流量本身是否稳定
参考答案：D
A．6.2×10-19C
B．6.4×10-19C
C．6.6×10-19C
D．6.8×10-19C
---Why can you speak English so fluently?
---Oh, I________ English in Shanghai International Studies University for four years.
A．studied
B． would study
C．was studying
D．had studied
