问题补充：
Food supplies in the flood-stricken area. We must act immediately before there’s left.
A. have run out
B. are running out
C. have been run out
D. are being run out
答案：
A. have run out
(答案→)B. are running out
C. have been run out
D. are being run out
解析：此题考查时态。“在遭受洪水袭击的地区，食物供给快完了。我们必须赶在(食物)一无所剩之前立刻行动起来。”从句子后半句我们可以知道受灾灾区食物还有少许，还没有到山穷水尽的地步，只是所剩已经不多。所以我们选用现在进行时表示“即将”。另外，run out这个词组没有被动语态形式。故不选D。
