so I choose to use the past simple passive. But their injuries are still evident at the present time, so I could have used the present perfect passive. There are no time phrases in this example to ...

When two things occurred in the past, the past perfect tense comes in handy to express them within a clause. In other words, unlike the present perfect ... The examples show that some people ...

One’s tense will vary depending on what one is trying to convey within their paper or section of their paper. For example, the tense may change between the methods section and the discussion section.