var handsonitems = from a in db.DltQuestionHandson

                                join c in db.DltBdChapter

                                on new { a.ChapterCode } equals new { c.ChapterCode }

                                select new

                                {

                                    a.PlantCode,

                                    c.ChapterCode,

                                    c.ChapterKnowledge,

                                    a.OrgSkillId,

                                    c.SkillCode

                                };

             var Jobevalitems = from a in db.DltQuestionJobeval

                                join c in db.DltBdChapter

                                on new { a.ChapterCode } equals new { c.ChapterCode }

                                select new

                                {

                                    a.PlantCode,

                                    c.ChapterCode,

                                    c.ChapterKnowledge,

                                    a.OrgSkillId,

                                    c.SkillCode

                                };

             var items = handsonitems.Union(Jobevalitems);