Original sentence: 1 trains made all local stops from 242nd Street to New Lots Avenue via the Clark Street Tunnel and IRT Eastern Parkway Line, to replace  trains, which terminated at 14th Street, at all times except late nights, when it terminated at Chambers Street in Manhattan instead.By this time, 1 trains only skipped Marble Hill – 225th, 207th and 145th Streets and 9 trains only skipped 238th, 215th, Dyckman and 157th Streets.Skip-stop service operated north of 137th Street – City College
Edited sentence: 1 trains made all local stops from 242nd Street to New Lots Avenue via the Clark Street Tunnel and IRT Eastern Parkway Line, to replace  trains (which terminated at 14th Street) at all times except late nights, when it terminated at Chambers Street in Manhattan instead.; during this time, 1 trains skipped Marble Hill – 225th, 207th, 191st and 145th Streets and 9 trains skipped 238th, 215th, Dyckman and 157th Streets.By this time, 1 trains only skipped Marble Hill – 225th, 207th and 145th Streets, while 9 trains still 238th, 215th, Dyckman and 157th Streets.Skip-stop service operated north of 137th Street – City College between the hours of 6:30 a.and 7 p