"Old Walt" is * 10 points
a criticism.
an ironic litany.
a satire of another poet's style.
an appreciation.
a limerick.

in my opinion, ap calculus was the most difficult. i often struggled with it a lot. however, i have gotten a lot better.

b and d

explanation:

the direction of the magnetic field produced by an electric current will change when the direction of the electric current changes. for example : if a current is flowing in a straight length of wire, the magnetic field is described by a concentric circle (using right-hand rule).