Doctors can collect it with a needle. But people who donate marrow must first have tests to make sure they are a good match for the patient.

VOA: special.2009.12.16

The innocent and the beautiful Have no enemy but time; Arise and bid me strike a match And strike another till time catch; Should the conflagration climb, Run till all the sages know.

天真者和美丽者,除了时光没有敌人；,起来，让我划一根火柴,再划一根，直到时光点燃；,假如大火升腾，就奔跑，直到所有圣贤都知道。

耶鲁公开课 - 现代诗歌课程节选