1. When our national security is at stake, we must do everything we can to restore peace.2. Working as a construction worker, he puts his safety in jeopardy every day.3. Working as a construction worker, he puts his safety at risk every day.
 at stake in jeopardy at risk這些片語都有「受到威脅」的意思，都是正統美語，非常好用。
Our teacher gave us a pactice test to help us prepare for the college entrance exam.