Student or Learner
Which one is correct "by using" or "using" or "through using" or "with using" in the following sentences?
By using a computer, we can learn to read and write.?
Using a computer, we can ...?
Through using a computer, we can ...?
With using a computer, we can ...?
Please give a full explanation.
1 and 2 are OK. 3 and 4 are unnatural although you might hear 3.