126. Over the past five years, Steven _____ two of his childhood dreams.
(A) has fulfilled
(B)has been fulfilled
(C)had fulfilled
(D) had been fulfilled

✅ 過去完成式範例（had fulfilled）：

例句：

Steven had fulfilled his childhood dream before he turned thirty.
史蒂文在三十歲之前就實現了他的童年夢想。
（這裡有兩個時間點：實現夢想是「更早的過去」，三十歲是「後來的過去」）

再看一個對比例句（強調順序）：

? 過去完成式：

She had finished her homework before her friends arrived.
（她朋友來之前，她已經完成作業。）

? 普通過去式（順序不明）：

She finished her homework when her friends arrived.
（可能她朋友來的時候才完成，或同時完成。）

✅ 對應你題目句子的改寫：

原句是：

Over the past five years, Steven has fulfilled two of his childhood dreams. ✅

如果改用過去完成式，就要補上另一個過去的參照點：

Steven had fulfilled two of his childhood dreams by the time he graduated from college.
（史蒂文在大學畢業前就已實現兩個童年夢想。）