She walked home by herself at night she knew that it was dangerous.A. onceB. asC. unless

问题补充：

She walked home by herself at night, she knew that it was dangerous.

A. once

B. as

C. unless

D. although

答案：

A. once

B. as

C. unless

(答案→)D. although

解析：考查连词。A一旦，曾经；B作为；C除非；D尽管

句意：她昨晚自己走回家，尽管她知道这样很危险。