20世纪60年代，由于软件生产的复杂性和高成本，使大型软件生产出现很大困难，人们称之为 ______ 。
参考答案：软件危机
Food supplies in the floodstricken area ________. We must act immediately before there's none left. [ ]
A. have run out
B. are running out
C. have been run out
D. are being run out
妊娠足月时的羊水比重＞1．025。
