How close would a supernova have to be to be lethal to land animals?

In an essay of 400 words, summarize the responsibilities of the three branches of the united states government and the system of checks and balances. what is the purpose of the system of checks and balances?

How did the mausoleum at halicarnassus transform society? 25 points pl i need

What potential crisis did eleanor roosevelt resolve on behalf of president roosevelt