Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Ketan kiran naik
odd one out here is river,as you have mentioned in questions itself..ans is river because a river flow from source to destination unlike other body which are constant at particular geographic locations.. some ans it as pool because they think pool is artificially created..if such is a thing lake can also be artificially created like Hussain Sagar lake or Sudarshan lake created by ancient rulers..so pool cannot be a correct answer here.
thank you so much Sir :)
most welcome kriti.