SELECT U.roadmark, U.number, U.sightingID FROM units U WHERE (U.roadmark = 'CN') AND (U.number = 3109) SELECT S.dt, S.trainnum, S.comments, L.name, L.provstate, S.locationID FROM sightings S, locations L WHERE (S.ID = 4544) AND (S.locationID = L.ID) SELECT S.dt, S.trainnum, S.comments, L.name, L.provstate, S.locationID FROM sightings S, locations L WHERE (S.ID = 4637) AND (S.locationID = L.ID)