17) The chemical, which attracts opposite sex insects of a species, is known as -

18) Consider the following statements:
1. In Macedonia, ethnic Albanians are a minority.
2. In Kosovo, Serbians are a majority.
Which of the statements is/are correct?

19) Synclines and anticlines are the terms associated with

20) Gondwana beds are known for their -

21) The Radcliff Line demarcates the boundary between