sentences: break can wreck base to fix down cooking & base can effect spices to sunny by physical proteins & physical weathering time vomiting weathering because of physical dryness ->  lichens can cause rocks to break down by chemical weathering  physical weathering is a mean of weathering & sand is formed by weathering ->  soil can be formed by chemical weathering  lichens can cause rocks to break down by chemical weathering & soil can be formed by chemical weathering -> lichens breaking down rocks can form soil