A downhole well fluid assembly, comprising: a plurality of sliding sleeves having a central throughbore and disposed on a tubing string deployable in a wellbore; each of the sliding sleeves having a housing having an outer diameter , an inner diameter , a central throughbore, and first and second ports , the first and second ports longitudinally offset from one another and communicating the central throughbore with the wellbore; each of the sliding sleeves having an insert and a retractable seat disposed in the central throughbore and being actuatable by a single ball deployable down the tubing string, the retractable seat being movable between a catch condition and a pass condition, the retractable seat in the pass condition being retracted into a slot of the central throughbore, the retractable seat in the catch condition being supported about its exterior diameter by the inner diameter of the housing ; each of the inserts in the sliding sleeves being actuated by the single ball engaging the retractable seat in the catch condition and moving in a longitudinal direction from a closed condition to a first opened condition, the insert in the closed condition preventing fluid communication between the central throughbore and the wellbore through the first and second ports , the insert in the first opened condition permitting first fluid communication between the central throughbore and the wellbore through the first port ; each of the retractable seats in the sliding sleeves in the first opened condition being in the pass condition and allowing the single ball to pass therethrough; and each of the inserts in the sliding sleeves being further movable in an opposite longitudinal direction from the first opened condition to a second opened condition, the second opened condition permitting second fluid communication between the central throughbore and the wellbore through at least the second port . a plurality of sliding sleeves having a central throughbore and disposed on a tubing string deployable in a wellbore; each of the sliding sleeves having a housing having an outer diameter , an inner diameter , a central throughbore, and first and second ports , the first and second ports longitudinally offset from one another and communicating the central throughbore with the wellbore; each of the sliding sleeves having an insert and a retractable seat disposed in the central throughbore and being actuatable by a single ball deployable down the tubing string, the retractable seat being movable between a catch condition and a pass condition, the retractable seat in the pass condition being retracted into a slot of the central throughbore, the retractable seat in the catch condition being supported about its exterior diameter by the inner diameter of the housing ; each of the inserts in the sliding sleeves being actuated by the single ball engaging the retractable seat in the catch condition and moving in a longitudinal direction from a closed condition to a first opened condition, the insert in the closed condition preventing fluid communication between the central throughbore and the wellbore through the first and second ports , the insert in the first opened condition permitting first fluid communication between the central throughbore and the wellbore through the first port ; each of the retractable seats in the sliding sleeves in the first opened condition being in the pass condition and allowing the single ball to pass therethrough; and each of the inserts in the sliding sleeves being further movable in an opposite longitudinal direction from the first opened condition to a second opened condition, the second opened condition permitting second fluid communication between the central throughbore and the wellbore through at least the second port . <EOS>