What constitutional clause allows congress to stretch its power?

Which of the following  bestillustrates a negative reinforcer?               a.  copland gives up candy to stave off chronic acid indigestion.    b.  nancy learns that she prefers chocolate over vanilla.    c.  carmine changes his major to english lit after failing a math exam.    d.  on a hot day, lindberg always drinks lemonade.

Which of the following leaders was a cambodian visionary who used this charismatic personality to reach dangerous goals

Answer asap and you read the following quote from hiram rhodes revels: i find that the prejudice in this country to color is very great, and i sometimes fear that it is on the in the space provided, reflect on revels’ quote. do you believe that attitudes toward race have improved since this quote was made? is there work still to be done? use examples to support your thoughts.