Pillow English Listening

• Mineral Groups
10957#10901 SIBLINGS CHILDREN 10901

○○○ silica tetrahedron ⪢⪢
#bookmark
10957#16437 SIBLINGS CHILDREN 16437

○○○ silicate ⪢⪢
-- crust, silicon, feldspar, quartz, potassium, plasioclase
10957#10958 SIBLINGS CHILDREN 10958