Caused the united states to enter world war i.
the revolution in russia
the assassination of archduke ferdinand
the german attack on belgium
the sinking of american ships

question as stated in comment

why did the chinese require the portuguese to pay for goods in gold and silver when trading?

choices

portuguese goods were less valuable than chinese goods.

the chinese already had a surplus of portuguese goods.

the imperial government wanted to stockpile gold and silver.

portuguese and chinese currencies were not exchangeable.

this a history q n in ancient time, theres no money exchange. so ans is portuguese and chinese currencies were not exchangeable.