综合写作：
In the western states of the United States, a new bridge was needed to carry car and truck traffic across the Colorado River. Plans were made to build a concrete arch bridge across the river, however, the plans called for the bridge to cross a wide canyon with rock walls rising far up above the river. There seemed to be too many challenges to building this bridge.
Extreme Width
First, because of the extreme width of the canyon, it was unclear how the workers and their equipment could be transported across the canyon to build the bridge. The traditional way would use large cranes (machines used to lift and move building materials) for this task. They would place a crane on the side of the canyon and then use the crane’s long arm – like component to carry workers and materials out over the canyon. Unfortunately, the canyon was so wide that there were no existing cranes that could carry the workers far out enough over the canyon.
Extreme Temperature
Second, the high temperatures at the construction site could prevent the bridge’s concrete from hardening properly. Concrete, a mixture of water, gravel and cement, starts out as a thick pourable substance that is affected by the temperature. If the temperature is too high as the concrete hardens, it will crack and lose strength. This was a problem since the temperature at the site often rose above 100 degrees Fahrenheit (37 degrees Celsius).
Financial Probelms
Third, there was difficulty finding a way to pay to build the bridge. Typically, the federal (national) government would agree to fully pay for a project of this magnitude before it starts. However, because there were so many unresolved issues, the federal government would only partially pay for the bridge. Without a commitment to pay the full amount, no one was willing to start the work.
学术写作：
Instructions: Your professor is teaching a class on education. Write a post responding to the professor’s question. In your response you should:
- express and support your personal opinion
- make a contribution to the discussion in your own words
An effective response will contain at least 100 words.
Dr. Achebe
As teachers play an invaluable role in shaping young minds and preparing students for the future, there is an ongoing discussion regarding their compensation. Some argue that teachers should be paid salaries comparable to other high – earning professionals like doctors, lawyers and business executives. Do you agree or disagree that teachers deserve salaries on par with those professions?
Claire
Teachers should receive salaries on par with other high – earning professionals. They work long hours preparing lessons, grading assignments, and supporting students. Without good teachers, we wouldn’t have doctors, lawyers, and executives. If we want to attract the best talent to this invaluable profession, we must compensate teachers accordingly. My favorite teachers inspired me and contributed greatly to my success.
Andrew
I don’t think teachers deserve the same high salaries as doctors or lawyers. Teachers get so much time off, with summer vacations and other long breaks. My aunt is a teacher and she’s always posting on Facebook about trips she takes or sleeping in during vacations. With all that time off, teachers shouldn’t earn salaries on par with year – round demanding professions.
