Why were railway authorities not present at the Wannsee Conference? They were unnecessary.
Transportation plans were already in place.
German and other Western European Jews had already been transported east. Western Jews were exempted from the Final Solution.

answer; /// i do believe that its napolean's conquest of spain;

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.