PAST SPECULATION
EGP #1230 | B2 | MODALITY / could Can use 'could have' + '-ed' to speculate about the past. Lexical range: N/A
她可能已经被杀了。
She ___could ___have been killed.
他可能在下班回家前把文件落在办公室了。
He ___could ___have left the documents at the office before going home.
她本来可以去参加聚会的，但她决定待在家里。
She ___could ___have gone to the party, but she decided to stay home.
他有没有可能说了什么话惹怒了老板？
___Could he ___have said something to upset his boss?
事故可能是在夜班期间发生的。
The accident ___could ___have happened during the night shift.