Чтобы заменить глагол "should" на "ought to" в предложениях, нам нужно просто подставить "ought to" вместо "should". Давайте посмотрим на каждое предложение и сделаем замену:

1. Bill should drive carefully. He is too tired.
   Замена: Bill ought to drive carefully. He is too tired.
2. You should stop smoking.
   Замена: You ought to stop smoking.
3. It’s a very good film. You should see it.
   Замена: It’s a very good film. You ought to see it.
4. He shouldn’t eat so much chocolate.
   Замена: He ought not to eat so much chocolate.
5. She shouldn’t work so hard. She looks tired.
   Замена: She ought not to work so hard. She looks tired.
6. I think, we should do something to help her.
   Замена: I think, we ought to do something to help her.
7. You should order this dish. It is very tasty.
   Замена: You ought to order this dish. It is very tasty.
8. They should have a rest after such a busy week.
   Замена: They ought to have a rest after such a busy week.

Таким образом, мы просто заменили "should" на "ought to" в каждом предложении. Это показывает, что оба выражения могут использоваться для выражения совета или рекомендации, хотя "ought to" может звучать немного более формально.