________ is now no ________ that global warming is a security threat to us all.
A.There; doubtB.There; needC.It; doubtD.It; need在线课程A
题意：毋庸置疑，全球变暖对我们所有人的安全来说是一个威胁。There is no doubt that..."……是毫无疑问的"，为固定搭配，符合题意。There is no need that..."……是没有必要的"。