What are three likely ways a research plan might be modified?
when you want to adjust the focus of a topic after learning more about it
when you need to review the guidelines of your research assignment
SE
when you need to find more sufficient evidence that supports your ideas
when you want to give credit to another author by citing the sources you used
when you need to provide evidence from more credible and trustworthy sources
Submit

when you want to adjust the focus of a topic after learning more about it

when you need to review the guidelines of your research assignment

when you need to find more sufficient evidence that supports your ideas

Options 1, 2 and 3.

Explanation:

Research plan is a short document which is not formal though but gives you an idea of on what your research would be based on. It is very logical and in a sequence manner.

The plan of your research should have the objectives, the aims on what your research is based on and it should have the preliminary data in it after choosing the subject properly which is worth researching at. Then it should be written in short way.

im gonna take a guess and say gas vans and chambers