Modaux anglais : American Dream et société

Read the following statements about the American Dream and choose the most appropriate modal verb ('must', 'should', or 'can') to complete the sentences based on the context of social values and individual effort.

1. Many immigrants believe that hard work is essential, so they ________ overcome obstacles to reach their goals.
2. According to the Declaration of Independence, the government ________ protect the rights of its citizens (it is a fundamental duty).
3. In a modern democracy, people ________ have the freedom to choose their own career path (it is a possibility offered by the society).