Put the verbs in brackets in the correct form (past simple or past continuous tense). 
1.When I came home my mom ...dinner for us. (to cook) 
2."What ...you ...about?" (to talk) — "Nothing serious." 
3.I'm sorry I couldn't join you yesterday. I ...for my exam, (to prepare) 
4.What... you ...at a minute ago? (to laugh) — It was the funniest joke I've ever heard. 
5.The spaceship captain ...the satellite which ...very fast, (to notice / to move) It was dangerous!

1.When I came home my mom was cooking dinner for us.2."What were you talking about?" — "Nothing serious." 3.I'm sorry I couldn't join you yesterday. I was preparing for my exam, 4.What were you  laughing at a minute ago? — It was the funniest joke I've ever heard. 5.The spaceship captain noticed the satellite which was moving very fast. It was dangerous!