题目

Facebook (脸谱网) friends cannot replace the real thing, say psychologists(心理学家).People are happier and laugh 50% more when they talk face to face with friends or via webcam (web camera) than when they use social networking sites, a study has found. Dr. Roberts, a famous lecturer at the University of Chester, said such websites don't appear to help make true friendships. Based on two questionnaires(调查表), he found there was no link between Facebook use and people with larger groups of friends.Dr. Roberts, whose work will be presented at the British Psychological Society13、下列各图经过折叠能围成一个正方体的是（　　）A、B、C、D、