Which of these belongs in the empty box?

electing a president
national power versus states' rights
slaves used to determine representation
taxation of exports

In the mid-1960s scientists created the two person gemini spacecraft that achieved many things in space. this new three person spacecraft took americans to the moon in july of 1969. a. discovery c. explorer b. columbia d. apollo

How many citizens of mexico does it take to equal the ecological footprint of the average citizen of the united states? it takes nearly three mexican citizens to equal the ecological footprint of the average u.s. citizen. it takes about 12 mexican citizens to equal the ecological footprint of the average u.s. citizen. it takes just over eight mexican citizens to equal the ecological footprint of the average u.s. citizen. two citizens of mexico equal the ecological footprint of one average citizen of the united states. they are essentially equal?

The most important units of the english armies which fought during the hindred years war were composed of