Which best explains what weakened the stock market in the late 1920's

I think the correct answer from the choices listed above is second option. The statement that best explains what weakened the stock market in the late 1920s would be that speculators bought on margin. Hope this answers the question. Have a nice day.

Knowing how Timur a ruler, made an impact that would disrupt the civilisations for centuries.

Explanation: As you read about Timur and how he matched Genghis Khan in brutality and desire to conquer far and wide. Made people believe that he wasn't an able ruler but he helped to begin a great cultural and economic flourishing in Eurasia.

He brought in the best  of what was available and made there of the places he invaded and plundered, his campaign to extend his empire succeeded after several bloody battles.

That left huge devastations in the defeated countries but all the wealth and loot including people were helped for the economic prosperity of central Asia.    

The major economic development that you get to see in Eurasia during 1200-1450 is through the growth of inter-regional trade and increasing the trading network. building of trade routes.

There was significant  development in cross cultural interactions, this further evolved into the literary, artistic and cultural exchanges. various religions such Buddhism, Islam, Judaism, Christianity, Hinduism and its core beliefs reached out other regions and shape societies.