His illness was mainly psychological.

They exported tea mainly to Europe.

I mainly eat vegetables for dinner.

The rock formation in this area is mainly composed of tuff.

Quartzite is a metamorphic rock composed mainly of quartz grains.

Limestone is a sedimentary rock composed mainly of calcium carbonate.

The increase in greenhouse gas emissions is mainly due to anthropogenic activities.

The menorah is a traditional Jewish symbol used mainly during the festival of Hanukkah.

Low German is a West Germanic language spoken mainly in Northern Germany.

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.