当只接通点火开关，而未起动发动机时，发动机故障灯点亮，表明故障灯电路良好。
参考答案：对
________ mothers can't come to the meeting because they have gone to Dalian.
A．Sally's and Jane
B．Sally and Jane's
C．Sally and Janes'
D．Sally’s and Jane's
有Na2SO3、BaCl2、Na2SO4、NaHCO3等四瓶溶液，只用一种试剂进行鉴别，应选用的试剂是[ ]
A．Na2CO3溶液
B．硝酸
C．硫酸
D．AgNO3
