III. b) (EA) and (FG) are skew.

c) (CN) is a subset of (ABCD)

(AD)= the intersection between (ABCD) and (ADH).

So, (CN) intersection (ADH) is equal to (CN) intersection (AD)

d) (ADH) is the same as (ADHE)

M belongs to planes (MNE) and (ADHE)

E belongs to planes (MNE) and (ADHE)

So, (ME) is the intersection of (MNE) and (ADH)

e) By Thales' theorem (MN) is parallel to (BD)

f) (MN) is parallel to (BD) which is parallel to (FH)

So, (MN) is parallel to (HEF)

g) a line passing through E parallel to (MN) and (FH)