20. **She left the room without saying a word**.
   - B. She left the room without saying a word

21. She left the room saying a word.
   - This sentence is not correct in this context.

23. My teacher doesn’t allow us **to talk** while he is explaining the lesson.
   - The correct answer is **to talk**.

24. We have plenty of time. We needn’t **rush**.
   - The correct answer is **rush**.

25. I promised **to arrive** on time. I mustn’t be late.
   - The correct answer is **to arrive**.

26. Mary and I are looking forward **to meeting** you.
   - The correct answer is **to meeting**.

27. I’m sure that he knows **how to operate** this new machine.
   - The correct answer is **how to operate**.

28. Psychiatrists and doctors have failed **to convince** people not to drink.
   - The correct answer is **to convince**.

29. The students are used to **studying** in the school library.
   - The correct answer is **studying**.

30. Our room needs **to be cleaned** up.
   - The correct answer is **to be cleaned**.

31. Mercury’s low gravity makes you **feel** very light in a spaceship.
   - The correct answer is **feel**.

32. “Was the test long?” “Yes, John was the only one **to finish** it.”
   - The correct answer is **to finish**.

33. A lot of needs **to be done** to the house before anyone can move in.
   - The correct answer is **to be done**.

34. It is about time you **studied** harder for the next exam.
   - The correct answer is **studied**.

35. If he really doesn’t feel like **going**, now I suggested that he should go out for some fresh air.
   - The correct answer is **going**.
#yuno