flash on and off造句

• Sparks were emitted from small black boxes and red lamps flashed on and off angrily .
  黑色的小盒子放出火花，红灯刺眼地忽亮忽灭。
• Fireflies flash on and off in the tall grass
  高高的草丛里，萤火虫忽隐忽现。
• Sparks were emitted from small black boxes and red lamps flashed on and off angrily
  火花从小黑盒里迸出，霓虹灯怒火般闪烁其辞。
• Sparks were emitted from small black boxesand red lamps flashed on and off angrily
  小黑盒子里迸出火花，红色灯泡发怒似地忽明忽暗。
• I suggest to install a bulb above the door . when there is no one passing through, the bulb does not light; when there are people approaching, it will flash on and off; when there are people pass through, it will light up
  我建议在门上方装一个灯泡，当无人通过时，他是关着的，当有人接近时，会一闪一闪的，当人从下方同下方通过时，灯泡会整个亮起来。