1.
My
friends went to experience the beauty of Mount Kilimanjaro last year, didn`t
they?
2.
Did
my friends go to experience the beauty of Mount Kilimanjaro last year?
3.
Did
my friends go to experience the beauty of Mount Kilimanjaro last year or month?
4.
Who
went to experience the beauty of Mount Kilimanjaro last year?
5.
When
did my friends go to experience the beauty of Mount Kilimanjaro?