私醫聯招 英文歷屆試題｜第 22 題
101 學年度
The cardiovascular system (21) the heart, blood vessels, and blood. From the heart, blood travels into the arteries and their smaller branches. It continues to the capillaries. Then, it moves to the branches of the vein structure before (22) to the heart. The heart serves as a pump. Arteries transport blood from the heart to body organs and tissues. Veins transport blood back to the heart.
- return
- returned
- returning
- has returned
提示
before 在這裡是介系詞還是連接詞？如果後面沒有主詞，該接哪種動詞形式。
正確答案
正解：C
詳解
A. return 為原形動詞，不能直接跟在介系詞 before 後面。
B. returned 為過去式動詞，同樣不能直接跟在介系詞後面。
C. returning 為動名詞，可直接接在介系詞 before 之後，符合「before + Ving」的用法，故為正解。
D. has returned 為現在完成式，是限定動詞形式，不能跟在介系詞後面。
