No other animal is as useful as the cow. (change into superlative degree)

Correct answer: The cow is the most useful animal.

• No other যুক্ত Positive degree কে Superlative degree তে রূপান্তর করার নিয়ম:
- Superlative Degree তে প্রথমে No other বাদ যাবে।
- Object (Positive degree -এর পরের) টি Subject হয়ে বসবে।
- Subject অনুসারে verb বসবে।
- the+ superlative degree বসবে।
- no other এর পরের Subject টি Object হয়ে বসবে।
- বাকি অংশ বসবে।

• More Examples:
- Positive: No other boy in the village is as good as Ripon.
- Superlative: Ripon is the best boy in the village.
- Positive: No other phase of life is as bad as poverty.
- Superlative: Poverty is the worst phase of life.

Source: Advanced Learner's Communicative English Grammar & Composition By Chowdhury & Hossain