题目

When Jenny Benson was eight, her mother took her to soccer practice for the first time.“She’s never played soccer before,” Mrs Benson told the coach.“I’m not sure how she’ll do.”Jenny ran onto the field and joined the other players. Over the next hour, Mrs Benson and the coach watched as Jenny out­ran many of the more experienced players.“I knew then that soccer would be Jenny’s sport.” Mrs Benson recalls. And she was right.It may have helped that Jenny had spent much of her time trying to keep up with her three brothers.“I wanted to be just like them,” Jenny says.“M已知数列{an}满足a1＝1，a2＝1，an＋1＝|an－an－1|(n≥2)，则该数列前2011项的和S2011等于(　　)A．1341 B．669 C．1340 D．1339