Conversation One
19.
A. The erupted Iava.
B. The destructive ash.
C. The unbearable heat.
D. The poisonous gas.
20.
A. Indonesia.
B. Yellowstone National Park.
C. The Wales.
D. The Great Britain.
21.
A. By observing the ordinary ones that have already erupted.
B. By studying the larger part of a volcano hidden underground.
C. By tapping to past information and modern technology.
