The sentence 'there are a lot of opportunities' is correct and usable in written English. You can use this sentence to talk about possibilities that exist for growth or development. For example, "With the new job openings, there are a lot of opportunities to advance in the company.".
There's almost nothing here in this field, so there are a lot of opportunities".
There are a lot of opportunities to grab.
but there are a lot of opportunities to see him".
There are a lot of opportunities in green technology for laid-off missile designers.
Seems like there's a lot of opportunities".
There's a lot of opportunities in the game.
There is a lot of opportunity".
Awesome tool! I started using it one year ago and I never had to look for another app
Ha Thuy Vy
MA of Applied Linguistic, Maquarie University, Australia