When I talked with my grandma on the phone, she sounded weak, but by the time we()up, her voice had been full of life.

A. were hanging

B. had hung

C. hung

D. would hang

桥式起重机的桥架是一种移动的金属结构，它承受载重小车的重量，并通过车轮支承在轨道上，因而是桥式起重机的主要承载构件。