过去完成时的运用 — 英语填空题

Choose the correct option: The explorers were exhausted because they ___ through…

After weeks of polar darkness, the crew finally saw the sun. The captain wrote t…

Choose the correct option to complete the sentence: If the radio operator ___ th…

Choose the correct option: Before the team of climbers reached the final camp, t…

By the time the rescue team finally reached the isolated camp, the climbers ___ …

By the time Maya reached the shelter, the other hikers ___ there. A. have arrive…