精选优质文档-倾情为你奉上2017届高三英语阅读理解记叙文2016 I卷 C I am peter Hodes, a volunteer stem cell courier. Since March 2012, Ive done 89 trips of those , 51 have been abroad, I have 42 hours to carry stem cells（干细胞）in my little box because Ive got two ice packs and thats how long they last, in all, from the time the stem cells are harvested from a donor(捐献者) to the time they can be implanted in the patient, weve got 72 hours at most, So I am always conscious of time.
