In which layer of soil does plants grows

Just below the subsoil there is a layer of:

Which is the layer just below the topsoi?

Which one of the following is a mixture of loose pieces of rock and particles of sand and clay?

What is used for making pottery?

Which animal makes burrows in the soil?

Which one of the following can hold very little air?

Which of the following is used to build roads?

Sand and gravel are mixed with cement to make:

On the basis of size of particles and amount of humus present in them, into how many kinds are the soil classified?