labored

工人们辛苦劳动了一整天来建造这座桥。

The workers ___labored all day to build the bridge.

病人因肺炎而呼吸困难。

The patient had ___labored breathing due to pneumonia.

他呼吸沉重而费力，显然是跑得太累了。

His breathing was heavy and ___labored, clearly exhausted from running.