Given two noun phrases (arguments) and relationship between them, form a sentence that expresses theses arguments with the given relationship.

Relationship: 'be city in', Argument/Subject 1: 'siena', Argument/Subject 2: 'tuscany'
Siena is one of the leading art cities in Tuscany .

Relationship: 'be president of', Argument/Subject 1: 'mugabe', Argument/Subject 2: 'zimbabwe'
Robert Mugabe became Zimbabwe 's first president after the establishment of majority rule and the official granting of independence from Britain in 1980 .

Relationship: 'hold in', Argument/Subject 1: 'conference', Argument/Subject 2: 'shanghaus'
After the 1987 and the 1995 System Dynamics Conferences held respectively in Shanghai and Tokyo , with the leadership and promotion of the Chapters of the System Dynamics Society , system dynamics is flourishing significantly in China and Japan .