Which is used in the laboratory for last drying of neutral gases?

Which substance is used in the laboratory for a fast drying of neutral gases ?

Which of the following substance (s) is/are used in laboratory for drying purposes ?

Which of the following substance (s) is/are used in laboratory for drying purposes ?

Hydrogen chloride gas is prepared in the laboratory using concentrated sulphuric acid and sodium chloride. Answer the question that follow based on this reaction : Name the drying agent not used for drying the gas.

Which is used for drying ammonia ?