7. It is not clear when __________, although there are many different theories. A. dinosaurs becoming extinct B. dinosaurs extinction C. dinosaurs became extinct D. did dinosaurs become extinct Answer : C: dinosaurs became extinct . the order is subject + verb, with no auxiliary. 8. The professor decided( (A) to allow )the students ((B) to take) the examination ((C)a second) time ((D) because) the low scores. Answer : D: because . The expression must be because of because it is followed by a noun phrase, the low scores. ...