The supreme court decision in Plessy Vs Ferguson is unconstitutional because THE SUPREME COURT RULING ALLOWED STATES TO DENY EQUAL PROTECTION TO ANY PERSON WITHIN ITS JURIDICTION.
The supreme court ruling which upholds the segregational law of the state of Louisiana is considered unconstitutional because it acts contrary to both the 13th amendment, which abolished slavery and 14th amendment, which prohibit some restrictive legislation on the part of the state.
The correct answer is idiom.
The Chinese government secluded their country from other nations to show its self-sufficiency. It is a condition of not requiring any help or support for survival or it does not trade with other nations. Foreign representatives or diplomats who go to the country were compulsory to bow to the Chinese emperor making him superior.