1) heat
2) pressure
erosion
3) chemically active fluids
weathering
Explanation:
There are some environmental factors which changes metamorphic rocks into sedimentary rocks. The factors are heat, pressure, temperature, water and chemically active fluids etc. Chemically active fluids speed up the process of weathering. Water goes in the pore of rocks and when the temperature increases, the water molecule expand which make cracks in the rocks and weathering occurs.