他吃力地把沉重的箱子搬到三楼。

He ___carried the heavy box up to the third floor.

那只猫受到惊吓时会把背弓起来。

The cat ___arched its back when it got scared.

老人步履蹒跚地穿过市场，吃力地拖着一个沉重的袋子。

The old man ___hobbled through the market, struggling with a heavy sack.

他们因为在后院亲热而被警告。

They got warned for ___humping in the backyard.