Vamos estudar para a prova e fazer os exercícios dos links abaixo:
http://www.englisch-hilfen.de/en/exercises/past_progressive_questions.htm
http://www.englisch-hilfen.de/en/exercises/past_progressive_questions2.htm
http://www.fortunecity.com/bally/durrus/153/gramex06.html#1
http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/pascon1.htm
http://perso.wanadoo.es/autoenglish/gr.pascon.i.htm
http://www.stufun.com/verbs/pastprogressive.php3
http://members.aol.com/adrmoser/hotpotatoes/myrtlebeach.html
http://www.inglesonline.com.br/exerciciosdeinglesonline/past-cont1.htm