[Photo/SIPA]
交通信号灯“红灯停，绿灯行（The green light allows traffic to proceed. The red signal prohibits any traffic from proceeding.）”。
“开绿灯”指交通路口打开准许行人车辆通过的信号，后多用于比喻“允许某事（allow someone to do something or something to happen, give the green light to）”，或“提供方便条件（make easier for）”。
例句：
zhèng fǔ yǐ jué dìng wèi zhè xiàng jì huà kāi lǜ dēng
政府已决定为这项计划开绿灯。
The government has decided to give the green light to the plan.
Editor: Jade