Among the following acid food item pairs. Which pair is incorrectly matched?

Which one of the following ore-metal pairs is not correctly matched?

Which type of lenses are prescribed for the correction of astigmatism of human eye?

Some substances, such as carbon dioxide change from a solid to a gas when heated, without becoming liquid in between. This is known as

Which of the following types of soils is favoured for extensive cultivation of cotton?

Which of the following is not considered as a renewable resource?