Facebook 是一个联系朋友的社交工具。大家可以通过它和朋友、同事、同学以及周围的人保持互动交流，分享无限上传的图片，发布链接和视频，更可以增进对朋友的 ...
parative Behaviour Research. Ã Correspondence to: Sonja E. Koski, Leverhulme Centre for Human Evolutionary Studies, Dept. of Biological Anthropology, University of Cambridge, Fitzwilliam Street, Cambridge CB2 1QH, UK. E-mail: sek39@cam.ac.uk ...