1.were discovered,discover,discovered
2.have slept,were sleeping,slept
3.were covered,covered,had covered
4.had drawn,has drawn,was drawn
5.would forget,will forget,would have forgotten
6.has created,created,was created
7.some,any,no
8.will be investigated,will investigate,is investigating
9.which,who,where
10.was planning,is planned,is planning
11.disappeared,will disappear,disappears​