For the second time in six months Bengals All-Pro quarterback Greg Cook undergoes shoulder surgery performed by Dr. Royer Collins today at the Cleveland Clinic and the club believes he’ll be ready for training camp in mid-July. The Aug. 17 procedure to correct his rotator cuff wipes out all of the 1970 season for the AFL Rookie of the Year and five weeks ago the Bengals select Augustana College quarterback Ken Anderson in the third round. Still, news of the setback stuns the Bengals. Assistant general manager Mike Brown says yesterday they think he can start throwing by April 1 and defensive line coach Chuck Studley, watching Cook work at Spinney Field, says he’s been telling friends how good and strong Cook looks.