第一部分 阅读理解（共两节，满分40分）
第一节 篇章阅读（共15小题；每小题2分，满分30分）
阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该题涂黑。
A
I am Peter Hodes, a volunteer stem cell courier. Since March 2012, I’ve 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 I’ve got two ice packs and that’s how long they last. In all, from the time the stem cells are harvested from a donor to the time they can be implanted in the patient, we’ve got 72 hours at most. So I am always conscious of time.
