Read the text below and think of the word which best fits each gap.Use only ONE word in each gap.
Surely(0)...one...of the most amazing sights on Earth is the display of natural light in th night sky known(1).........the Northern Lights.It is something everyone should see(2).........least once in their life.
These lights,(3).........are mainly visible in Àrctic region,are caused when material from the sun reaches the Earth'smagnetic field.On the(4).........the most common colours are green and red,although sometimes blue ar purple lights can be seen.They often look like brightly coloured clouds dacing across the sky,in displays that can last several hours.
(5).........you want to observe the Northern Lights,it's best to get as close to the North Pole as possible durng the winter,in(6).........of the extreme cold.Seeing the lights in the short Arctic summer is not really possible in view of the fact that they are only visible in darkness,and during the months(7)..........the sun never sets there is daylight 24 hours day.
Weather conditions also(8).........a big diference.The lights cannot be seen(9).........the sky is clear,so there must be no fog or heavy clouds.Bright moonlight can also reduce the intensity of the lights and because of(10).........you should avoid any nights that have afull moon.
