What is used for making pottery?

Just below the subsoil there is a layer of:

The vegetable which grows well in the clay soil:

In which layer of soil does plants grows

Which one of the following has particles smaller than gravel?

Which one of the following is darker in color due to the presence of dead and decaying plants and animals?

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

Name the soil which is considered as best:

Sand and gravel are mixed with cement to make:

Which one of the following is mainly a mixture of sand and clay?