Please remember that I can't answer every question in the comments area below lessons. Here are a few questions that people asked recently:
1) Which is correct: "we students are having a party" or "us students are having a party"?
"We students" is correct because it's the subject of the verb. If you delete the word "students", the sentence doesn't make sense if you say "us are having". Note: you might hear native speakers saying "us students", but this would be in very informal contexts.
2) Is it a good idea to write "It is disagreed that" or "It is believed that" to make task 2 essays seem more academic?
Be careful. If you write "it is believed", you are saying "people generally believe". Therefore, it does not tell the examiner what your opinion is. If the question asks for your opinion, do not use these phrases to express it. You need to write "I disagree" or "I believe".
3) What is the difference between "in + year" and "by + year"?
When you write "in 2007", you are only talking about that year. For example, "House prices were at their highest point in 2007" does not tell us what happened before 2007.
We use "by 2007" to express what happened in the period before and leading up to that year. For example, "House prices had risen to their highest point by 2007" suggests that prices were rising in the years leading up to 2007.
Notice that I used the past simple "were" with "in 2007" and the past perfect "had reached" with "by 2007".