Can I increase my score from 670 to +700 by having as many practice tests as possible?

practice tests do help.. but they're not helpful in learning new material. they're good for benchmarking and letting you know where your weaknesses are. 20 days left is still enough time to be able to drill your weaknesses... this is the only way to get from 670->700... in your case i'm not sure what they are but I would say that if you can increase your verbal score a bit.. and be able to pair that with a 47 Quant score you'll be able to get a 700