Looking on the internet deeply has found these results:

there's a lot of concerns is the most popular phrase on the web.

there are a lot of concerns 1648,000 results on the web	there's a lot of concerns 12,780,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I imagine there's a lot of concern for Josh. The board is voicing a lot of concerns. in Egypt and Tunisia I understand that there are a lot of concerns And agendas here. I had a lot of concerns with his consistency with the medication. And, although it's not very large, there are a lot of concerns about that. but there are also a lot of concerns. Many of the things that are happening are a reason for joy	The board is voicing a lot of concerns. Now, that's a lot of concern for someone who ruined you career in the military. And, although it's not very large, there are a lot of concerns about that. I imagine there's a lot of concern for Josh. I understand that there are a lot of concerns And agendas here. In North America, we call this Astroturfing, and Astroturfing is very common now. There's a lot of concerns about it. I imagine there's a lot of concern for Josh. I had a lot of concerns with his consistency with the medication.

there are a lot of concerns

1648,000 results on the web

there's a lot of concerns

12,780,000 results on the web

More popular!

The board is voicing a lot of concerns.
Now, that's a lot of concern for someone who ruined you career in the military.
And, although it's not very large, there are a lot of concerns about that.
I imagine there's a lot of concern for Josh.
I understand that there are a lot of concerns And agendas here.
In North America, we call this Astroturfing, and Astroturfing is very common now. There's a lot of concerns about it.
I imagine there's a lot of concern for Josh.
I had a lot of concerns with his consistency with the medication.