Complete the sentences so that they mean the same as the

Complete the sentences so that they mean the same as the original sentences.
1. My sister started studying maths at 4 o'clock.
She is still studying it.
My sister ____ maths since 4 o'clock.
2.Jane is really selfish - she doesn't like anyone else.
Jane is really selfish - she only ____ .
3.It is a long time since Kate emailed me.
Kate hasn't ___ a long time.
4, Tom can take care of himself. Bill can take care of himself, too.
Tom and Billcan both ____ .
5. Nobody helped us - we did it on our own.
Nobody helped us - we did it ____.