History of India - Test - 08
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The serial number of the first MAC ever produced was 2001 .. More >>
1.the time period during which military and civilian agencies are prepared for an enemy air attack
2.the condition in which combat aircraft are airborne and ready for an operation
3.the warning signal that begins an period of preparation for an enemy air attack
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Greatest Technological Inventions of the Past 25 Years
CSI owes a debt of gratitude to Sir Alec Jefferys. Without his genetic fingerprinting technique, a big chunk of their show would be mission. Thanks to Sir Jefferys, law enforcement can identify people based on any bit of DNA left behind at a crime scene. Though he made the technology commercially available in 1987, it took a few years for it to catch on. Even today, convicts can be released from prison if the DNA evidence proves them innocent.
At is used to talk about position at a point.
It's very hot at the centre of the earth. Sometimes we use at with a larger place, if we just think of it as a point: a point on a journey, a meeting place, or the place where something happens.
Turn right at the next traffic-lights.
You have to change trains at Didcot. On is used to talk about position on a line. ON
The plane stops for an hour at Frankfurt.
Let's meet at the station.
There's a good film at the cinema in Market Street.
His house is on the way from Aberdeen to Dundee. On is also used for position on a surface.
Stratford is on the River Avon.
Come on — supper's on the table! In is used for position in a three-dimensional space (when something is surrounded on all sides).
Id prefer that picture on the other wall.
There's a big spider on the ceiling.
I don't think he's in his office. We say on (and off) for buses, planes and trains.
Let's go for a walk in the woods.
I last saw her in the car park.
He's arriving on the 3.15 train. In addresses, we use at if we give the house number.
There's no room on the bus; let's get off again.
She lives at 73 Albert Street. We use in if we just give the name of the street.
She lives in Albert Street. We use on for the number of the floor.
She lives in a flat on the third floor. Learn these expressions:
in a picture in the sky on a page