In 23-5 quiz, was also about pronoun references. But in this time, It was with different type of question. It comes with correct the sentence. And now I will write some sentences from the quiz and I will explain the mistakes. We have a staff of experienced technicians that will service your copier within two hours of a service call. In this sentence we should not use “that” because technicians are people, So we should use “ who” instead of “that”. In Professor Jamal's class, you are lucky to earn a C. I think it’s good sentence but there is small misleading mistake which it is “ you”. Better use students to make the sentence more clear.