Once travelling was a hazardous process. People had to make lots of preparations for days together to make a journey of even fifty kilometers' distance. But science has made travelling much easier. Besides cars, trains, ships etc., we have now aeroplanes. In the present era people can go for holidays in any place in the world without any hassles and these journeys are very simple and pleasant. So many wonderful things have been invented by science, which could not even be imagined a few decades back. People did not have any idea about computers, laptops, television, mobile phones, microwave cooking etc. But today the situation is such that people can't even think of living without these scientific wonders. Countless wonderful things have been contributed by science to make life much more comfortable and enjoyable.