Difference between ...
I can't understand the difference between "they have just been injected" and "they were injected".
Can you explain that to me ? (In french if you can but not necessarily"Thank you !

Question

Difference between ...
I can't understand the difference between "they have just been injected" and "they were injected".
Can you explain that to me ? (In french if you can but not necessarily"Thank you !

Answer

I think 
they have just been injected means Il viennent tout juste d'être injectés.
they were injected means Ils ont été injectés (or implantés).

Answer

In my opinion "they have just been injected" means that it has happened just a few minutes ago as to "they were injected" could mean that it could have happened days or months ago.