.—Did you return Fred’s call?—I didn’t need to I’ll see him tomorrow. A. thoughB. unlessC

问题补充：

.—Did you return Fred’s call?

—I didn’t need to I’ll see him tomorrow.

A. though

B. unless

C. when

D. because

答案：

A. though

B. unless

C. when

D. because

解析：根据句意思，只有填because意思最通顺。