Some English midterm questions are not clear.

39. A. Investigate the structure of "discovery+object+object complement" and the usage of it pronouns. It is a formal object, which means the infinitive "tell him what happened", and its practical meaning is: "find out what his parents told him what happened ← object necessary ← object complement".

15.d. investigate the differences between what, who and who in object clauses. Who and who are subjects and objects in clauses, which refer to people and things respectively. Here, who is the object of address, and a perfect person is the object complement, which means: after these years, I have a new understanding of people who are traditionally called perfect.

13. Answer. Investigate the word order of the object clause. Using declarative sentences in object clauses, are does not move forward. Choose where according to the meaning of the sentence

14.d. Investigate the word order of the object clause and the meaning of tell. If you choose b, tell should be changed to ask.

45. A. Investigate the word order and tense of the object clause. The last sentence is prompted by the simple present tense.

16. Answer. Examine the attributive clause. Who refers to a person with a subject in the attributive clause. What does it mean?

26.b.where is a good place to eat? Investigate the word order of object clauses.

35.b. Investigate the word order of the object clause.