交通警察发出这种手势信号时要减速慢行。
参考答案：对
曝光时间大于0.5s，测量管电流的最佳仪表是
A．V表
B．A表
C．mA表
D．mV表
E．kV表
Tom kept quiet about the accident ________ lose his job. [ ]
A. so not as to
B. so as not to
C. so as to not
D. not so as to
