Writing Feedback / TOEFL - should boys and girls learn in separate classrooms? [8]

I believe they can learn lessons together. They don't need separate classrooms.

Research Papers / Research paper on Death Penalty -- specific criminal cases [6]

A deeply divisive problem in the United States is the use of the capital punishment, as few countries in the industrial world besides the United States really allows the death penalty. The monetary cost of the death penalty is very large, though the moral argument over the capital punishment being used is another problem entirely.

Writing Feedback / Being happy with a job is more important than having a high salary? [7]

A high salary can be lost and you spend the money easily. But if you're happy with your job, you'll enjoy your work and the lessons you learned and the memories you have with your co-employees can be treasured and precious.