Ответ:
Part 1.
1. Lily and Phil are having dinner in the restaurant.
Лили и Фил ужинают в ресторане.
2. Lily and Phil were having dinner in the restaurant.
Лили и Фил ужинали в ресторане.
3. Lily and Phil will be having dinner in the restaurant.
Лили и Фил будут ужинать в ресторане.
Part 2.
1. Have Lily and her mother prepared the present for Jack?
Лили и ее мать приготовили подарок Джеку?
2. Had Lily and her mother prepared the present for Jack?
Лили и ее мать приготовили подарок Джеку?
3. Will Lily and her mother have prepared the present for Jack?
Лили и ее мать приготовят подарок для Джека?
Part 3.
1. Schoolchildren aren't go to school in summer.
Школьники не ходят в школу летом.
2. Schoolchildren didn't go to school in summer.
Школьники не ходили в школу летом.
3. Schoolchildren won't go to school in summer.
Школьники не пойдут в школу летом.