Find the odd number from the following series.

Direction: In the following, select the related word from the given alternatives.
Heat : Convection :: Space : ?

Direction : In the following question, select the related word form the given alternatives.
Coconut : Shell :: Letter : ?

Direction: In the following question, select the related letters from the given alternatives. 

TRACK: MECTV: : POND : ? 

Select the word-pair in which the two words are related in the same way as the two word-pair.

Author: Book

Knoll : Hill :: Eclogue: ?

An ‘Island’ is related to ‘Sea’ in the same way as an ‘Oasis’ is related to ‘_____’.

Direction: In the following question, select the related letters from the given alternatives. 

EHJ : KNP : : SVX : ?