SANTA CLARA, Calif. – The answers to all of the San Francisco 49ers' receiving troubles were on display on the practice field Wednesday.Mario Manningham had his first full practice since being activated to the 53-man roster, and Michael Crabtree worked for the first time since being cleared to practice.Mannigham is expected to play Sunday against Carolina. After practice, Manningham sounded supremely confident. He hasn't played since he injured his knee last December, but he said he is "full go" and is preparing to play Sunday.