A.12個(gè)月以上 B.1-2個(gè)月 C.3-4個(gè)月 D.4-6個(gè)月以上
A.10~15m B.20~25m C.15~20m D.15~25m
A.大理巖 B.玄武巖 C.安山巖 D.花崗巖