Sentence:They were a loose [e1]confederacy[/e1] of various Arab [e2]lineages[/e2] who were forged together in the eighteenth century by a common way of life and amalgamated in the twentieth century under their famous Shaykh (Sir) 'Ali al-Tom (1874-1937).
 e1: confederacy. 
 e2 : lineages.
Answer: Member-Collection(e2,e1)