Of the four books, the red one is the -

The roads of Rajshahi are wider____ Water-logging is one of the worst problems in our country. (Positive) I thought that _ was the last one. Dhaka is one of the biggest cities in Bangladesh. (Positive) No animal is so big ____ the blue whale. It burns the prettiest of any wood. (Positive) Corruption is one of the worst evils. (Positive) The roads of Dhaka are wider ....... The Padma is one of the biggest rivers in Bangladesh. (Positive) He is the best boy in the class. (Positive)