Which of the following sentences is an obligation?

Tengo que terminar un trabajo esta noche para mi clase de historia.
Me gustaría sacarme buenas notas en matemáticas este semestre.
Voy a ayudar a mi mamá a limpiar la casa este fin de semana.

Both the first and last one could potentially be an obligation but im sure it’s first one

700 pounds. woodchucks are not adept to moving timber compared to beavers/groundhogs/all those other furry creatures.
some biologist measured the inside volume of a typical woodchuck burrow and stated that if wood filled the whole instead of dirt, the woodchuck would have chucked about 700 pounds worth.