Can someone PLEASE tell me the difference between preterite and imperfect tense.

Explique por qué la teoría de la tectónica de placas resolvió los problemas con la hipótesis de la deriva continental.

Drag the correct label to each picture. each label can be used more than once. identify the type of weathering seen in each picture. the choices are chemical weathering or mechanical weathering.

Completa la oración con la voz pasiva con se. the cake was eaten. la torta. (there's no options, just phrase this in the passive tense, do not use google translate)