Question

malaria is the most common disease. (change into positive) ​

Answer 1

The adjective in the given sentence can be changed into positive degree as shown and explained below:

Explanation

In the given sentence superlative degree has been used.  The superlative degree can be changed into positive degree in the following manner:

No other disease is as common as malaria.

Though the degree has been changed, but the thought and the idea in the sentence is the same.  

Answer 2

‘No other disease is as common as malaria’ is a positive sentence.

Explanation:

• There are three degrees in English. They are positive degree, comparative degree and superlative degree. The three degrees for common are: common, more common and most common.  

• The positive degree is common. Hence the Statement should start with, "No other disease" then the verb is to be used and finally the Statement should end with 'as malaria'.  

• The rest of the statement is to remain as it is.

Learn more about positive sentence

How to covert positive sentence into negative sentence​

https://brainly.in/question/12780264

Formula of positive sentence and negative sentence with 10 example

https://brainly.in/question/4385754