--It’s reported that the new underground line has been completed. --Yes, but it hasn’t been made clear ________ it’s to be opened to traffic on time as planned.
PART TWO LANGUAGE KNOWLEDGE
SECTION A
Directions: Beneath each of the following sentences there are four choices marked A, B, C, and D. Choose the one answer that best completes the sentence.
21.It was not ______ he took off his dark glasses ______ I realized he was Liu Xiang.
A.when; that B.until; when C.when; then D.until; that