According to the report, this virus was
问题:
According to the report, this virus was never known, which had claimed countless lives, _____ it was
accidentally found by a doctor. [ ]
A. unless
B. since
C. so that
D. until
According to the report, this virus was never known, which had claimed countless lives, _____ it was
accidentally found by a doctor. [ ]
A. unless
B. since
C. so that
D. until