•A bolt from/out of the blue (idiom) -

Something completely unexpected or surprising; that which occurs without any warning.（晴天霹雳，平地一声雷）

Examples:　　

1.News that they were going to dissolve our company came like a bolt from the blue.　　

2.It was a bolt out of the blue when the prime minister announced his resignation.

•On the verge of sth (idiom) -

At the point when something is about to happen or is very likely to happen.（濒临…，处于…的边缘）

Examples:　　

1.The company was on the verge of going bankrupt.　　

2.The country was on the verge of becoming prosperous and successful.

•On a par (with sth/sb) (idiom) -

At the same level or standard as (someone or something else).（与…相若，可与…媲美）

Examples:　　

1.Property in this bustling city is valued even higher, almost on a par with London.　　

2.Her writing at its best is considered to be on a par with Charles Dickens.

•Room for manoeuvre (idiom) -

Opportunity to make changes or to do things differently in order to produce a better result.（回旋余地，调整空间）

Examples:　　

1. Parliament has more room for manoeuvre than is thought.　　

2. Small businesses have limited room for manoeuvre.

•In one stroke, at a stroke (idiom) -

If something happens at a stroke or in one stroke, it happens suddenly and completely because of one single action.（一下子，一举而成）

Examples:　　

1.The disease wiped out 40 million rabbits at a stroke.　　

2.When the economy crashed, thousands lost their jobs, their homes, and their pensions in one stroke.