Understanding Global Warming and Filling the Blanks

The passage discusses global warming, its causes, and its impacts. It explains that the Earth's temperature is rising, leading to a phenomenon called global warming or climate change. While this can be a natural process, the text highlights the significant role of human actions in accelerating it. It mentions the burning of fossil fuels and deforestation as major contributors.

Analyzing Blank Number 3 in the Passage

The sentence containing blank number 3 is: "Although it is a natural phenomenon, human action is the (3) ______ cause of global warming." This sentence presents a contrast: global warming is natural, but human action is identified as a key factor. We need to find a word that describes the kind of cause human action represents in this context.

Let's look at the options provided for blank 3:

1. Major
2. Slowest
3. Rapid
4. Mutual

Evaluating Options for Blank 3

We need to choose the word that best fits the blank and makes sense in the sentence:

• Major: This word means significant, important, or primary. If human action is the "major" cause, it means it is the principal or most important cause contributing to global warming. This fits the context, as the passage goes on to list specific human activities like burning fossil fuels and deforestation as causes.
• Slowest: This word refers to speed. Saying human action is the "slowest" cause of global warming doesn't make sense in the context of driving climate change.
• Rapid: This word also refers to speed. While human action might *lead* to rapid changes, calling human action itself the "rapid" cause is grammatically awkward and doesn't accurately describe the *nature* of the cause (as opposed to its effect or speed).
• Mutual: This word means shared or reciprocal. "Mutual cause" would imply that global warming causes human action, or that the cause is a result of interaction in a shared way, which doesn't fit the context of human action driving climate change.

Based on the analysis, "Major" is the most appropriate word to describe the primary or significant role human action plays as a cause of global warming, contrasting it with the natural phenomenon aspect.

Therefore, the sentence reads: "Although it is a natural phenomenon, human action is the major cause of global warming."

Conclusion on Blank 3 for Global Warming Passage

The most appropriate option to fill in blank number 3 is "Major".

The correct option is 1: Major.

Revision Table: Global Warming Causes

Additional Information: Human Impact on Climate Change

While Earth's climate has changed throughout history due to natural factors like variations in solar radiation or volcanic eruptions, the current rate of warming is significantly faster and directly linked to human activities. The burning of fossil fuels for energy, transportation, and industry releases vast amounts of carbon dioxide ($\text{CO}_2$) and other greenhouse gases into the atmosphere. Deforestation removes trees that absorb $\text{CO}_2$, further exacerbating the problem.

These human-caused emissions enhance the natural greenhouse effect, trapping more heat and causing the planet to warm. This warming leads to various impacts, including rising sea levels, more frequent extreme weather events, disruption of ecosystems, and effects on sectors like agriculture, as mentioned in the passage.

Reducing emissions through transitioning to renewable energy, improving energy efficiency, sustainable land use, and conserving forests are crucial steps to mitigate the human impact on global warming and climate change.