作为科学家,我们明白巨大进步源于思想自由,因此,我们有责任声明这一自由的价值;有责任教育人们不必害怕疑惑,而要欢迎疑惑、讨论疑惑;有责任强烈要求这一自由,这就是我们对于后世的义务。
As the world's longest man-made canal, the Grand Canal is a vast waterway system in the north-eastern and central-eastern plains of China, (run) from Beijing in the north to Zhejiang province in the south.
The Grand Canal is a magnificent hydraulic (水利) project in human history. (construct) in sections from the 5th century BC onwards, it was completed in 611 AD due to the (establish) of Sui Dynasty and it reached a new peak in the Yuan Dynasty, linking five of China's main river basins. (original), it was built to transport grain and later (ship) other commodities.The regions along the canal gradually developed into the trade center of China it was considered as the economic artery (动脉) in ancient China. It also helped the evolution of Chinese culture enhancing communication between the south and the north.
The Grand Canal represents the (great) masterpiece of hydraulic engineering in the history of mankind. It is outstanding example of human creativity. Still a major means of internal communication today, it (play) an important role in ensuring the economic prosperity and stability of China over the ages.
Sustainable tourism, which is becoming (increasing) popular nowadays, is not just about seeing the sights — it is also about connecting with people and their cultures, (make) a positive impact on the places we visit and enhancing (增进) opportunities for the future. So, how can we be sustainable tourists?
It is important to travel in environmentally friendly manner. Getting to a tourist destination by airplane, which greatly increases our carbon footprint, ( have) a huge impact on the global environment. While avoiding flying is not always (practice) , we can help improve the environment by travelling on local public transport or even, on foot wherever possible. When at the hotel, we can reduce our impact by cutting back on water consumption and not having our bedding and towels (wash) everyday. We also need to protect the local culture. When visiting temples or churches, where a strict dress code may (require) , we should dress properly. While travelling, we should respect the right to privacy. We must ask for (permit) before taking pictures of the local people, are human beings and not on display.
summary, being a sustainable tourist comes down to respect for nature, culture and people.