测量相位的指示仪表可以用电动系、铁磁电动系、电磁系或变换式仪表，工程上常用的是（）。
参考答案：电动系和变换式
“She's not a dancing teacher, is she?” “_____.”
A．Yes, and she isn't
B．Yes, but she was
C．No, but she isn't
D．No, but she was
根据我国票据法的规定，票据保证______。
A．应当是单纯保证，不单纯保证不影响票据保证的成立B．应当是单纯保证，不单纯保证的，票据保证不成立C．可以是单纯保证，也可以是不单纯保证D．不分单纯保证与不单纯保证
