1 You had to count/You will have to count
2 He had to control/He will have to control
3 They could watch/They will be able to watch
4 Retailers couldn't sell/Retailers won't be able to sell
5 The USA didn't have to regard/The USA won't have to regard
6 students had to spend/students will have to spend
7 could believe/will be able to believe
8 could offer/will be able to offer
9 couldn't make/won't be able to make
Company owner must be in his room. You may talk to him.
May I come in? Yes, you may.
Government shouldn't interfere into privat sector. (мой выбор модального глагола основывался на собственном понимании вопроса. Shouldn't - означает, что ему не следует вмешиваться. Но можно и поставить can't, тогда это будет означать, что государству вмешиваться не разрешено. Можно и mustn't - тогда это значит, что существует какой-то закон. Видите - выбор модального глагола зависит от собственного понимания ситуации)
Can he count the expenses?
Our company can invest 1 million dollars into the production.
The company can't agree with our conclusions.
Running government company must be based on cooperation with the government
Our country economy shouldn't be in stagnation.
Can you name me several skilled workers?
What should I say about global economy condition?