Summer isnt' just the time for cable to debut new efforts. In the wake of the "Downtown Abbey" popularity, PBS is capitalizing on all things English. With the Olympics and the queen's diamond jubilee, the network will launch T"Queen & Country" ( July 1-22), a four-part series that examines the monarch's reign. Also, "Michael Wood's Story of England" (July 3-17) tells the country's 2,000-year history through the people of Kibworth, Leicestershire. For mystery buffs, "Masterpiece Mystery!" debuts a one-off film, "Endeavour" (July 1), a prequel to the classic "Inspector Morse." The fifth season of "Inspector Lewis" (starting July 8) returns viewers to Oxford.