Which of the following factors influences whether a volcano erupts explosively?
A. The concentration of aa in a magma
B. The concentration of water in a magma
C. The concentration of phosphorus in the magma
D. The concentration of volcanic bombs in the magma

Which of the following are keys to consider whether an eruptions are explosive or not?
A. Gas content
B Silica content
C. Soil content
D. Water content​