kept a lookout的用法和样例：
- Keep a lookout for the red lantern signal.
- Jackie kept a lookout perched on Puff's gigantic tail.
- K>> Jackie kept a lookout perched on Puff's gigantic tail.
- Using Interior Command To Keep A lookout For Corporation risks.
- Jack asks a friend at the LAPD to keep a lookout for his daughter.
- When night came she went forth with silent foot and obtained food for herself and her kittens, but feigning to be afraid, she kept a lookout all through the day.