Use the prompts to make sentences.

1. t hey are working at the scientific problems at present. they aren`t working at the scientific problems at present.are  they working at the scientific problems at present? 2.he  was waiting for you yesterday at 3 o'clock. he wasn`t waiting for you yesterday at 3 o'clock.was  he waiting for you yesterday at 3 o'clock? 3. s he is translating a german article now. she isn`t translating a german article now.is  she translating a german article now? 4.t hey were listening to the lecture yesterday at 6 o'clock. they weren`t listening to the lecture yesterday at 6 o'clock. were they listening to the lecture yesterday at 6 o'clock? 5.h e will be preparing for the exam tomorrow all day long. he won`t be preparing for the exam tomorrow all day long. will he be preparing for the exam tomorrow all day long?