Конечно! Вот переписанные предложения с использованием "if" и "unless" в соответствии с примером:
Unless she gets some rest, she won't be able to continue her work.
If she doesn't get some rest, she won't be able to continue her work.If Chris doesn't have a stomachache, he should go to school.
Unless Chris has a stomachache, he should go to school.If we don't hurry, we will miss lunch.
Unless we hurry, we will miss lunch.Unless I exercise regularly, my body won't stay healthy.
If I don't exercise regularly, my body won't stay healthy.If Chloe doesn't study, she won't get good marks.
Unless Chloe studies, she won't get good marks.If you don't learn some stress-management techniques, you won't know how to deal with stress.
Unless you learn some stress-management techniques, you won't know how to deal with stress.If I don't call, they will be worried.
Unless I call, they will be worried.If Mr and Mrs Jones don't leave the house at 9:00 am, they will miss their flight.
Unless Mr and Mrs Jones leave the house at 9:00 am, they will miss their flight.Unless we think positively, the problem will be worse.
If we don't think positively, the problem will be worse.
Если нужны ещё примеры или объяснения, я готов помочь!