Which continent came in mongol influence and rule

Until about 20 years ago, most scholars of Mongol-era China emphasized the destructive influence of Mongol rule.

One major scholar of Chinese history even wrote: "The Mongols brought violence and destruction to all aspects of China's civilization. [They were] insensitive to Chinese cultural values, distrustful of Chinese influences, and inept heads of Chinese government." This assessment fits in with the traditional evaluation of the Mongols as barbarians interested primarily in maiming, plundering, destroying, and killing.

As a 13th-century Persian historian wrote of the Mongol campaigns: "With one stroke a world which billowed with fertility was laid desolate, and the regions thereof became a desert, and the greater part of the living, dead, and their skin and bones crumbling dust, and the mighty were humbled and immersed in the calamities of perdition."

It is true that the Mongols, in their conquest of both North and South China, did considerable damage to these territories, and that great loss of life certainly ensued. The population of North China did decline somewhat, though earlier estimates that there was a catastrophic decline in population have subsequently been revised.

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.