lug|lugged|lugging

我们不得不费力地把那台沉重的钢琴搬上三楼。

We had to ___lug the heavy piano up to the third floor.

我们费力地把沉重的沙发搬上了三楼。

We ___lugged the heavy sofa up to the third floor.

他艰难地拖着沉重的行李箱上楼。

He was ___lugging the heavy suitcase up the stairs.