trip wire

基本解释

The tent was protected with a trip wire but it didn't stop the bear getting inside as they slept.
被保护的帐篷与旅行线，但它并没有停止，因为他们承担越来越里面睡。
As the name implies, this gives you the ability to control how data is packed (and unpacked) for its trip across the wire.
顾名思义，这使您能够控制数据的打包（和解包）方式，以在线路上进行传输。
Or more specifically, when will the US cross the trip wire and try to prevent China from protecting its resources, and will the US do it deliberately to try to keep China down.
更确切的说，当美国越线并阻止中国保卫其资源，美国将会做的就是压制中国。
blog.sina.com.cn

But even the boss can hit a trip wire.
FORBES: Not East or West
On an out-of-town trip Carlsbad state senator Joseph Gant Jr. read a wire- service story -- by chance -- about the Lyons fiasco and got on the telephone to other Carlsbad influentials.
FORBES: How Carlsbad got WIPPed

A tripwire is a wire stretched just above the ground, which sets off something such as a trap or an explosion if someone touches it.