It is the dress rehearsal. It’s time for the Dallas Cowboys’ offense to sing and dance – uh, we mean run and pass – like it will on opening night in 15 days.Tonight’s next-to-last preseason game will give the starters a chance to play into the third quarter, perhaps longer. It will be their longest action of the preseason. None of the starters are expected to play in the final tune-up next week.“Hopefully we’ll move the ball, get in the end zone, be productive, and put more than one drive together,” tight end Jason Witten said. “That’s what we want to do.”That’s what the first-team offense has yet to do so far in the preseason. The starters have played in five drives over two games, but have not scored a touchdown. Twice, drives have ended in turnovers.“We need to protect the football,” Witten said. “We didn’t do a very good job of that. It’s something we’ve talked about [doing] all off-season.”He does not expect it to be easy against the Bengals and their defensive coordinator Mike Zimmer, a former Cowboys coach.“Good defense up there in Cincinnati with Coach Zimmer,” Witten said. “It’ll be tough for us, but this will be the time to get everything tuned up and get some confidence going into the Giants game.” 1Ball security: After six turnovers last week, the Cowboys promised they would rededicate themselves to protecting the ball. Backup quarterback Kyle Orton might not play much tonight, but the Cowboys would like him make better decisions when he does. 2Special teams: Cowboys special teams haven’t been very special this preseason. Fumbled punts, late hits, a blocked field goal. They need a clean game tonight. 3Run-pass selection: As expected, the Cowboys have leaned heavily on the pass with Tony Romo back in the saddle. The only game where they had more run plays than pass plays was the Hall of Fame game, when Romo did not play. 4Free at guard: Doug Free shifted from right tackle to right guard this week. The Cowboys might decide to make the switch stick and move on from David Arkin. 5Safety coverage: Look for extended action from safeties Barry Church and Will Allen. They should be in on plenty of tackles, but for Church the challenge is pass coverage. Will he show the range and ball skills the Cowboys believe he has developed?