He did not work hard. He failed the exam

Question 19. He did not work hard. He failed the exam.
A. Even though he failed the exam, he didn't work hard.
B. Unless he had workedhard, he would have failed the exam.
C. If he had worked hard, he would have passed the exam.
D. However hard he worked, he failed the exam.
Question 20. Mary lost the ticket. She didn't go to the concert.
A. If Mary had lost the ticket, she would have gone to the concert.
B. Had Mary not lost the ticket, she would have gone to the concert.
C. Hadn't Mary lost the ticket, she would have gone to the concert.
D. If Mary hadn't lost the ticket, she would go to the concert.
Question 21. You don't try to work hard. You will fail in the exam.
A. Unless you don't try to work hard, you will fail in the exam.
B. Unless you try to work hard, you won't fail in the exam.
C. Unless you try to work hard, you will fail in the exam.
D. Unless do you try to work hard, you will fail in the exam.
Question 22. "Why don't we go out for drinks?", said Jenny.
A. Jenny recommended why we went out for drinks.
B. Jenny said why they didn't go out for drinks.
C. Jenny suggested going out for drinks.
D. Jenny asked why they didn't go out for drinks