Have I correctly used ‘sake,’ ‘complicated,’ ‘get concerned,’ and ‘like’ in these sentences?

Have I correctly used ‘sake,’ ‘complicated,’ ‘get concerned,’ and ‘like’ in these sentences?

Tommy and Danielle said: “Mr. and Mrs. Jacobs, our university professors, give their time, knowledge, talents, and efforts for the sake of us students. They find ways to simplify lessons that seem to be complicated. They get frustrated when we get low marks. They get concerned when we have problems, even outside the school. They are like our second parents.”