15.Scratch a single itch
16.Restrain endless heather
17.Second rare birds if prey
18.unfinished pie unfortunately stale
19.2001 contained in a child's plaything
20.Law reversed by royalty
Thank you lots
As well as No 15 I'm puzzled why they are 'amazing' activities - pretty standard fare really.
Perhaps peggym will let us have more details of the quiz, in line with the site's guidelines, that may throw more light on it.