Help please i need for a test

Arguably one of the most important inventions of the 20th century was a) the transistor. b) air conditioning. c) the vacuum cleaner. d) radio broadcasting.

What did the brown board of education decision do? o a it established 'separate but equal" segregation o b. it supported cultural segregation in the classroom o c. it banned racial discrimination everywhere. o d. it ruled that segregation in schools is unconstitutional

Need it now explain gorbachev’s policy of glasnost. how did this policy change the soviet union?