It was not until the 1960s and 1970s archaeologists made real progress in unders
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It was not until the 1960s and 1970s archaeologists made real progress in understanding the script.
A.when
B.which
C.how
D.that
试题答案
D
解析：考查固定句型。It was not until …that …这是对not until…句型的强调句。故选that。