Questions

The study of flags is called Vexillology and the art of flag design is called as Vexillography. The man who studies flags is called as Vexillologist.

A complex sentence is a sentence that contains an independent clause and one or more dependent clauses.

If two clauses are connected with a coordinating conjunction, it's a compound sentence.

If two clauses are connected with a subordinating conjunction, it's a complex sentence.

Phage typing is based on the fact that bacterial viruses attack specific cells. Phage typing is a method used for detecting single strains of bacteria. It is used to trace the source of outbreaks of infections. 

Jharia, a town in the sate Jharkand in India is famous for coal mines and resources. It plays an important role in the economy and development of the state.

Stamps are what travel around the worldstaying in one spot. Slippers and walking stick can also travel around the world but they will not stay at one spot. So they are eliminated.