be thankful (或 grateful) for small mercies

be relieved that an unpleasant situation is alleviated by minor advantages

慶幸不利情況已略有改善

have mercy on (或 upon)

show compassion or forgiveness to

寬恕；對…有憐憫之心

may the Lord have mercy on her soul.

愿主寬恕她的靈魂。

leave someone/thing to the mercy of

expose someone or something to a situation of probable danger or harm

聽任…由（可能有危險或危害的形勢）擺布

the forest is left to the mercy of the loggers.

森林任憑伐木工隨意砍伐。

throw oneself on someone's mercy

intentionally place oneself in someone's hands in the expectation that they will behave mercifully towards one

特意懇求（某人）寬恕

at the mercy of

Without any protection against; helpless before

任由…擺布；在…面前無助

drifting in an open boat, at the mercy of the elements.

在一敞篷船中漂泊，任由暴風雨擺布