Cause

Which are correct:
-There is a strange smell here.
1-The smell is caused by the work done next door.
2-The smell is from the work done next door.
3-The smell is produced by the work done next door.
(Meaning: The work done next door is what causes the smell.)


-I can smell a gas here.
5-There is some gas. It is from the work done next door.
6-There is some gas. It is produced by the work done next door.
(Meaning: The cause of the existence of this gas is the work done next door.)

Gratefully,
Navi.