Answer:
They keep the discussion on track.
Answer:
There are real differences in the populations in different countries. Demographics are particularly important - that's things like average age, or where people live.
Explanation:
But not all testing data is the same - some countries record the number of people tested, while others record the total number of tests carried out (many people need to be tested more than once to get an accurate result).
Answer:
Probably the last one, Anne's family moves.
Explanation:
The war is the biggest thing of these.
