We cannot but work hard for the development of our country. (Affirmative) (Change the sentence)

We are Bangladeshi. (Interrogative) = Aren't we Bangladeshi? 

Bangladesh is our homeland. (Complex) = It is Bangladesh which is our homeland. 

It is a small country. (Negative) = It is not a big country. 

Though it is a small country, it is blessed with many natural resources. (compound) = It is a small country but it is blessed with many natural resources. 

No other country in the world is so green as Bangladesh. (comparative) = Bangladesh is greener than any other country in the world. 

The fruits of Bangladesh are tastier than any other fruit in the world. (Positive) = No other fruit in the world is as tasty as the fruits of Bangladesh.