Definition: If something is monotonous, it is boring because it stays the same. Level: C1
他的声音如此单调，以至于让每个人都睡着了。
His voice was so ___monotonous that it put everyone to sleep.
工厂装配线通常涉及单调的任务。
Factory assembly lines often involve ___monotonous tasks.
演讲者的声音单调，缺乏任何节奏或变化。
The speaker's voice is ___monotonous and lacks any rhythm or modulation.
