_____ deep down in the earth, the dead forests rotted away and became coal.

A. Buried 　 B. Burying　 C. To bury 　 D. Being buried

_____ deep down in the earth, the dead forests rotted away and became coal.

A. Buried 　       B. Burying　     C. To bury 　      D. Being buried

_____ deep down in the earth, the dead forests rotted away and became coal.

_____ deep down in the earth, the dead forests rotted away and became coal.

1. A.
   Buried
2. B.
   Burying
3. C.
   To bury
4. D.
   Being buried

_____ deep down in the earth, the dead forests rotted away and became coal.