Which statement is correct?
There is a thick layer of humus in dry deserts.
There is a thick layer of humus in cold deserts.
There is a thin layer of topsoil in tropical rain forests.
There is a thin layer of topsoil in temperate areas.
There is a thick layer of humus in dry deserts.
There is a thick layer of humus in cold deserts.
There is a thin layer of topsoil in tropical rain forests.
There is a thin layer of topsoil in temperate areas.