Fill in the blank can be difficult because it is unclear what type of question it is until you have read the passage. Regardless when you are reading this type read for the conclusion and any premises.
The conclusion of this argument is "this figure is likely exaggerated" indicated by the word because and a reason following. The premise is that there is a universal practice of insuring against fire but not earthquake."
it is our job to determine what this universal practice
...
The conclusion of this argument is "this figure is likely exaggerated" indicated by the word because and a reason following. The premise is that there is a universal practice of insuring against fire but not earthquake."
it is our job to determine what this universal practice
...