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 ____.