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47. All passengers must fasten their seat belts.
A. They have to fasten their seat belts now.
B. They don't have to fasten their seat belts.
C. They can fasten their seat belts.
D. All passengers shouldn't fasten their seat belts.
48. Lenny didn't have to see the head teacher after all.
A. It wasn't necessary for Lenny to see the head teacher.
B. Lenny went to see the head teacher.
C. Lenny is waiting to see the head teacher.
D. Lenny wants to see the head teacher.
49. You don't need to buy me a birthday present.
A. You must buy me a birthday present.
B. It's not necessary to buy me a birthday present.
C. You mustn't buy me a birthday present.
D. It is necessary to buy me a birthday present.
50. It is necessary to finish the work today.
A. You need to finish the work today.
B. You mustn't finish the work today.
C. You don't have to finish the work today.
D. You can finish the work today or not.