Complex sentence: Mr. Chin opened air scouting to all and as a result, Air Scouting spread and flourished after 1972 and expanded to 18 Air Scout units in 5 Regions of Scout Groups in Hong Kong.
Split into simpler sentences: Mr. Chin opened air scouting to all and as a result, Air Scouting spread and flourished after 1972. There are 18 Air Scout units in 5 Regions of Scout Groups in Hong Kong.