Изменить предложения, добавив вместо must - have to.
Например: Gregory must get up at 7 o'clock every day./Gregory will have to get up at 7 tomorrow.( Да, и кстати, сначала сказано что он должен делать каждый день, а надо сказать что он должен сделать завтра). Вот предложения:
1) Gregory must make breakfast every day.
2) Gregory must do morning exercises every day.
3) Gregory must take his dog out every day.
4) Gregory must go to school every day.
5) Gregory must water the flowers every day.
6) Gregory must prepare tea for the family in the evening.