Is the following paragraph okay?
Syria turned into a battlefield in 2011. Since then, many Syrian people have been driven out of their country. A great majority of them are flooding into Europe.
Is the following paragraph okay?
Syria turned into a battlefield in 2011. Since then, many Syrian people have been driven out of their country. A great majority of them are flooding into Europe.
There's nothing wrong with it.
It starts with simple past, sets a new time frame with since then and uses have been driven to establish the fact of the exodus, and describes the result with are flooding, a process that is continuing up to the present from the reservoir of displaced people.
Yes, Appolyon, your fused sentence works fine.
In fact, the flooding is subsequent to have been driven.
(I am answering the OP's question/comments here, because the software here suddenly won't let me make comments anywhere. It also no longer supplies a window to display the result of what I am typing in the composition window, and it asks me to complete a capcha to post or edit my answer. What a mess...)