1. The dictator ruled with a merciless hand, suppressing any opposition.
独裁者以无情之手统治，镇压任何反对势力。

2. The merciless winter storm left thousands without power or shelter.
残酷的冬季风暴造成成千上万的人失去了电力和住所。

3. The merciless competition in the business world can be overwhelming.
商业界的无情竞争可能令人不知所措。