这道题的正确答案是：
句型转换,一空一词.
They needn't pay for their meals at work.(同义句转换)
They (don't have to) pay for their meals at work.
needn't= don't have to 没必要
I have to clean all the windows this Friday.(改为一般疑问句)
(Do you have to ) clean the windows this Friday?
Tina is talking with Fred.(对画线部分提问,画线：Fred)
(Who is) Tina (talking with)?
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