If you see the heading of the Objective Question of Fill in the Blanks, You will see very clearly writte the Words " Rewrite the Sentence Filling the Blanks" so for that you have to write whole sentence Filling the Blanks Space with your answer & underline that word/Phrase you have entered.
For Other things as True & False or One word ans Etc you need not Rewrite the Whole Question but may write only the Required Ans. True / False with the Reason in brief, As wriing only True / False will not give you Full marks. Marks are spread as 1 Marks for Ans True / False & 1 Mark for Reasoning. Recently I have seen them clearly mentioning in the Paper itself that answers without Reasons will not be awareded marks. I hope all your Doubt about Objectives must have become clear
All The Best for the Exams