过去完成时与过去完成进行时 — 英语词汇题
题目
用括号中动词的过去完成时或过去完成进行时填空。When the curator entered the archive at noon, Mei was still checking the records; she ___ (work) on them since early morning and continued until 2 p.m. By the time the archive closed, she ___ (check) every record, and the final list was complete.