1. 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 Explain : This is an embedded question, and thus the order is subject+verb, with no auxiliary 2. The professor decided to allow (A) the students to take (B) the examination a second (C) time because (D) the low scores Explain : The expression must be “because of” because it is followed by a noun phrase, the low scores 3. If the driver’s own car………….damaged, the favorite probably would have won the race A. Had not been B. Not C. No had been D. Has no be Explain : Because use the past perfect construction in past condition 4. Having (A) withdrawn from the race, the candidate decided supporting(B) his opponent despite (C) the opponent’s representing the other (D) political party Explain : Decide must be followed by the infinitive, “to support...