mega mix 71

new to cryptics - need some help

1d=the sort of shelf that extends a long way underwater-c?n?????t?l
16a=midlers lost her head over layabouts=??l?r?
21a=reckon i'm included in estate-??t?m?t?
60a=unit of atmospheric pressure-?i?l?b??
52d=one who repeats things,in other words-i?t???r?t?r

and is 4d=trifles for heartless tomboys----toys

thanks--------thorn36