a lookout tower的用法和样例：
- A greenhouse, a scndeuk and an extra-large barn-size tool shed and a lookout tower by the shore are also constructed in the similar fashion, alone.
- Keep a lookout for the red lantern signal.
- He stood on the lookout tower and gazzed into the wilderness.
- A huge iceberg was suddenly spotted by a lookout.
- The general posted a lookout on top of the hill.