受到不公平待遇后，她完全有理由生气。

She has good ___cause to be angry after the unfair treatment.

气候变化是全球科学家担忧的一个重要原因。

Climate change is a significant ___cause for worry among scientists worldwide.

市场的突然崩溃让投资者有充分理由对经济感到担忧。

The sudden market crash gave investors ample ___cause for concern about the economy.