Questions

The black flag signifies a protest.

Stars twinkle because they’re so far away from Earth that when light from the stars passes through the atmosphere, it is bent countless times due to refraction, making it look like as if they were blinking. The sun and other planets doesn’t twinkle because it’s too close to Earth compared to other stars.

Author of the book A journey  is Tony Blair

Donald John Trump (born June 14, 1946) is an American businessman, television personality, politician, and the 45th President of the United States.

Carbon monoxide is a common atmospheric pollutant in the world which is produced in combustion process in automobiles and industries. It has no smell and cannot be seen.

Defence Research and Development Organisation (DRDO) has developed an unmanned, remotely operated tank which has three variants - surveillance, mine detection and reconnaissance in areas with nuclear and bio threats. It is called Muntra. 

We know that, there are 7 continents in the world. They are :

Asia, Africa, Australia, North America, South America, Europe and Antarctica.

Africa - 53 countries

Asia - 48 countries

Europe - 45 countries

Antarctica - 0 countries

Hence, the continent Africa has most number of countries with 53 countries and in second place Asia has 48 , third Europe has 45 countries.