综合写作：
Natural gas is a mixture of hydrocarbons, nitrogen, and other gases. It occurs naturally underground. Natural gas is a source of energy: it can be used for heating, transportation, and for generating electricity.
New methods of extracting natural gas have led to a dramatic increase in the production and use of natural gas in the United States in recent years. However, many critics argue that this recent trend has created serious problems. The critics recommend that the production of natural gas in the United States be reduced.
Not a Clean Energy Source
Natural gas is not a clean source of energy. Like coal or oil, natural gas is a fossil fuel. Using fossil fuels creates greenhouse gases that trap heat close to Earth’s surface and contribute to climate change and pollution. The critics suggest that trying to increase the use of cleaner sources of energy, such as solar or wind power, would be a much better long – term energy strategy than increasing the production and use of natural gas.
Wastewater
To force the gas out of underground rock layers, toxic chemicals and water are pumped into the ground under high pressure. The process creates toxic wastewater. The wastewater comes back to the surface, where it is collected and disposed of. Unfortunately, improper disposal of wastewater used in gas extraction has led to contamination of rivers and drinking – water supplies, causing major environmental and health problems.
Impact on Local Communities
The critics also point out the negative impact of gas extraction on nearby communities. The drilling rigs for extracting gas from the ground are noisy, as are the trucks used to take the gas away. The noise and the bright lights needed for operating gas – extraction equipment can be very disruptive and unpleasant.
学术写作：
Instructions
Your professor is teaching a class on sociology. Write a post responding to the professor’s question.
In your response you should do the following:
- Express and support your opinion.
- Make a contribution to the discussion in your own words.
An effective response will contain at least 100 words.
Dr. Diaz
This week, we’ll be discussing the concept of “multi – age classes” in primary schools, where students of different ages are grouped together in the same classroom. Some think that this method enhances the learning environment, while others feel it might present challenges. Do you agree or disagree with the following statement? Primary educational institutions should form multi – age classes, that allow for 2 – 3 years age differences within the same class. Why or why not?
Andrew
I think it is a good idea to have multi – age classes in primary schools. This setup can help younger students learn from older ones, and older students can develop leadership skills by helping their younger classmates. It also reflects real – world situations where people of different ages work and interact together.
Claire
Well, it sounds like a bad idea to have multi – age classes in primary schools. The main reason is that children at different ages are at different stages of development and may have different learning needs. A one – size – fits – all approach might not meet everyone’s needs effectively.
