- Excuse me, can you tell me the way to the Summer Palace?

- ___________.You can ask the policeman over there.

“大树底下好乘凉”体现了（    ）

甲图是一氧化碳还原氧化铁的装置，乙图是炼铁高炉示意图．下列叙述中正确的是（　　）

Security devices at airports are ______ to spot weapons that could be used by terrorists.