Răspuns :
North---Future---High---To link---irregular---inexactly---known---the first---the richest---foreign---uncommon---to build---unsimilar---to stop
For 'ordinary' and 'common', which are synonymous, you have 'uncommon/unusual'. For 'similar', the correct opposite is 'dissimilar/different'. Last but not least, for something so concrete and realistic such as 'the past', you would probably need a similar truthful temporal context, say, 'present' because future does not exist.