You could check out: http://deltaeducation.com.au/
I need to disclose that I work there, so I might have vested interests in making the recommendations. However they do offer a two week free trial that you can use to try it out and see how you go.
I don't get the idea behind this - when I'm marking a student's paper it actually pleases me if he/she has gone over the lines (with relevant, correct information that answers the question) - it shows that they've done their work and are keen to demonstrate what they know.
I guess it could get...
That's one of the most misguided and ignorant things I've ever heard. If you want to be a doctor, all you need is a passion for your potential career, whether it be to help people or to excel in the ranks of what's a very challenging and engaging profession. I know a myriad of humanities...
It's still DC. The split-ring commutator causes a hard swap of the direction of the current (i.e. it goes from +V to -V instantly) - the current is exactly the same, you've got a very simple external mechanism simply reversing the path of the current. AC current involves the smooth variance of...