Food supplies in the flood-stricken area . We must act immediately before there’s nothing

问题补充：

Food supplies in the flood-stricken area . We must act immediately before there’s nothing 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：本题考查动词时态和语态。分析题干语境可知，食品供应即将耗尽。runout为不及物动词短语，不能使用被动形式，由此可排除C和D两个选项。B选项为现在进行时态，可以表示将来，符合题意。因此，正确答案为B选项。