Tallest structures in the world

   The tallest man-made structure in our world  is Burj Khalifa, a skyscraper in Dubai that reached 828 m (2,717 ft) in height on 17 January 2009. The  CN Tower  in Toronto, Canada, standing at 553.3 m (1,815 ft), was formerly the world's tallest completed freestanding structure on land. Opened in 1976 and unfortunately it was surpassed in height by the rising Burj Khalifa on 12 September 2007.  and of course there are some others pretty tall structures in our world that are not mentioned above.

but if you observed these structure more closely, it was very obvious that they all ave one thing in common, that the base of their structures are always wider than their tops. in fact, most of these buildings are in a  somewhat   cone shape , which help them to stand. Tomorrow our Teacher, Mr.Chung will ask us to build a structure with only newspaper. and the highest will won, what a exciting class and what a waste of newspaper.