2/ the ISO 45001 say to assess the OH&S opportunities, what does by mean of assess ,is it same when we say determine opportunities?
1/OH&S opportunities and other opportunities as per clause 220.127.116.11 is asking you to have a process to assess both of these types of opportunities. OH&S opportunities (clause 18.104.22.168 a) are any opportunities that may exist to improve your OH&S performance within your organization. This could include adapting work to make it safer, organizing work in way that reduces workplace injury or eliminating hazards that may exist in the workplace. An example would be replacing a cleaning chemical that is a known carcinogen with a safer chemical to clean parts in your facility.
Other opportunities (clause 22.214.171.124 b) come from outside of your organization such as changing legal compliance obligations or changes in external issues. An example of one of these other opportunities could be : if you find out that a supplier will not be able to provide you with a chemical that is critical for your product, and you can’t find th e chemical anywhere else. This could be an opportunity to find a safer chemical to replace the chemical that is being made obsolete.
In both cases, you assess these opportunities to decide which need to be addressed with planning actions (clause 6.1.4).
2/ To assess the opportunities is to decide what, if anything, needs to be done about them. You determine which opportunities exist, then you decide if you will do anything about the opportunity, and if so, you then plan to work towards achieving the opportunity.
For a more thorough discussion of opportunities in ISO 45001:2018, see the article: What are the new requirements for risks and opportunities according to ISO 45001?, https://advisera.com/45001academy/blog/2018/04/25/what-are-the-new-requirements-for-risks-and-opportunities-according-to-iso-45001/