Question

This is the worst disease I have come accross
(change into Positive & Comparative degrees)​

Answer 1

The given sentence is in superlative degree. 'one of the greatest'. 'The' is always used in superlative degree and the adjective 'greatest' is also in the same degree.

Positive degree: Few honours in the world are as great as the Nobel Prize.

Comparative degree: The Nobel Prize is greater than most other honours in the world.

Answer 2

Answer:

positive: No other disease is as bad as this I have come across.

Comparative:This is worse disease than many other I have come across.