Questions

Error is in third part. Every, each, either, neither are adjectives that are always followed by a singular pronoun. Every being singular takes singular subject. Therefore ‘their ideas’ should be replaced with’ his/her idea’.

Propene, being an alkene, and propyne, being a alkyne, are distinguished using the common chemical tests namely ammoniacal silver nitrate or ammoniacal cuprous chloride. Ammoniacal silver nitrate is also called as Tollen's reagent.

India   signed   a   historic   deal   to develop    the    strategic    port    of Chabahar  in  Iran  and  agreed  on  a three-nation    pact    to    build    a transport-and-trade corridor through   Afghanistan   that   could help  halve  the  time  and  cost  of doing  business  with  Central  Asia and     Europe.     Developing     the  Chabahar  port  was  seen  as  crucial for  India  because  it  will  not  only allow New Delhi to bypass Pakistan and access global markets but also counter    China’s    expanding influence   in   the   Indian   Ocean region. But the project’s land route through   Afghanistan   remains   a security headache