An analysis of the best results of the world's men's and women's marathons over the past decade shows that the women's record has improved 7 times over the men's record, however, the fastest men's marathon runners are still much faster than the fastest women's marathon runners. Can we infer from this? ["The training level for men's marathon runners needs to be improved.", "Women's marathon runners have greater development potential than men's marathon runners.", "The current women's marathon record is faster than the men's marathon record ten years ago.", "Ten years ago, the women's marathon was more than seven times the record."]