to cause something to remain in its original state without any significant change
beyond the appropriate or necessary amount, often to a point that is undesirable or harmful
a permanent change in global or regional climate patterns, including temperature, wind, and rainfall
the condition of lacking enough money or income to afford basic needs like food, clothing, etc.
the process of people moving from rural areas to urban areas, resulting in the growth of cities and the expansion of urban areas
the rapid spread of an infectious disease within a specific population, community, or region, affecting a significant number of individuals at the same time
the act or process of making a substance or place dirty or polluted, especially by dangerous substances
污染,杂质
used to show that something happened or is true, even though there was a difficulty or obstacle that might have prevented it