Choose the appropriate word which can be substituted for the given sentence: '$A$ person sent on an official mission'.

Choose the appropriate word which can be substituted for the given sentence: $A$ strong craving for alcohol.

Choose the appropriate word which can be substituted for the given sentence: The study of ancient societies.

Choose the appropriate word which can be substituted for the given sentence: 'One absorbed in his own thoughts and feelings rather than in things outside'.

Choose the appropriate word which can be substituted for the given sentence: Removing people from a place of danger.

Choose the appropriate word which can be substituted for the given sentence: 'Habitually silent or talking little'.