Seaweeds are important source of -

For manufacturing of glass, which among the following is used as a source of silica?

Which among the following are essential constituents of Portland cement ?

Which one of the following is not a pigment?

With reference to 'Baking Soda', which of the following statements is/are correct? 1. It is Sodium hydrogen carbonate. 2. It is used in fire extinguishers.

The surface of the concrete structure of a new construction is covered with straw/gunny bags by wetting. This is done to :