Here are the correct answers to the questions in the image:

16. **A. have learned** (Correct: "By the end of last year, George had learned English for two years.")
17. **B. has painted** (Correct: "She has painted the picture when I came.")
18. **C. has swept** (Correct: "While I was sweeping the floor, Mrs. Parker began cooking.")
19. **A. was washing** (Correct: "She was washing dishes already.")

Feel free to ask if you have more questions!