（www.pewsocialtrends.org/2010/06/25/childlessness-up-among-all-women-down-among-women-with-advanced-degrees/?beta=trueutm_expid=53098246-2.Lly4CFSVQG2lphsg-KopIg.1utm_referrer=https%3A%2F%2Fwww.google.com%2F）

1978年，湖北云梦秦57XO墓葬群中的uCgN代墓M45出土过一件竹3OlO，弓臂为两UYBu长竹片相接vMCO成，接口处HkjO两块短竹片4Dw1住，表面髹pRhF漆，弭为骨w1l5。