irony

Her voice heavy with irony, Simone said, "We're so pleased you were able to stay so long." (= Her voice made it obvious they were not pleased.)

西蒙娜口气里明显带有讽刺地说：“你能呆这么长时间，我们真高兴。”

The irony (of it) is that the new tax system will burden those it was intended to help.

具讽刺意味的是，新的税收制度反而将使该制度本打算要帮助的人背上沉重负担。