D. They are comprised 20 species and many cultivated forms 16. We chose to find a place for the nigh. We found the bad weather very inconvenient. A. Bad weather was approaching, so we started to look for a place to stay. B. The bad weather prevented us from driving any further. C. Seeing that the bad weather had set in, we decided to find something to spend the night. D. Because the climate was so severe, we were worried about what we’d do at night. 17. The first runner came in. The second runner followed him closely. A. The first runner who closely followed by the second came in. B. The second runner close ly followed the first one came in. C. The second runner who was closely followed came in with the first one. D. In came the first runner, closely followed by the second. 18. Martin missed his flight because he had not been informed of the change in flight schedule. A. Martin missed his flight, though he had been informed of the change in flight schedule. B. Martin had been informed of is flight delay, which was due to the change in flight schedule. C. Not having been informed of the change of the flight schedule, Martin missed his flight. D. Not having missed his flight, Martin was informed of the change in flight schedule. 19. The deciding match of the series will take place tomorrow afternoon, weather permitting. A. The match that will determine the series’ winner will be played tomorrow afternoon if the weather is fine. B. Even if the weather is bad, tomorrow’s match, which will decide the winner of the series, will be played. C. The weather will probably not permit the match to be played tomorrow afternoon. D. It would be unfortunate if the weather did not permit tomorrow’s match to be played, as it will determine the winner. | 
Đáp án B thành “known”
Giải thích: Chủ ngữ là “The struggle” nên phần rút gọn sẽ là Ved (bị động)