Question

Что за время?
I couldn't get into the flat because I had lost my keys

I was working in the report the whole night yesterday

She will graduate from college next year

Answer 1

I couldn't get into the flat because I had lost my keys .( Past Perfect -had lost ),

I was working in the report the whole night yesterday .(Past Continues- was working).

She will graduate from college next year.(Future Simple - will graduate).