a) is watching

b) is running

c) is Beth studying

d) are cooking

e) is snowing

f) is working

g) are dancing

g) are having

i) are the boys playing

j) are selling

k) is walking

Na letra b, it usado com o verbo run faz sentido quando se refere a algum animal ou alguma coisa. Também seria possível ser o verbo "rain","chover" onde ficaria is raining