Complete the sentences so that they mean the same as the original sentences. 1. My sister started studying maths at 4

1. My sister started studying math at 4 o\'clock. She is still studying it. My sister has been studying math since 4 o\'clock. 2. Jane is really selfish - she doesn\'t like anyone else. Jane is really selfish - she only likes herself. 3. It is a long time since Kate emailed me. Kate hasn\'t emailed me for a long time. 4. Tom can take care of himself. Bill can take care of himself, too. Tom and Bill can both take care of themselves. 5. Nobody helped us - we did it on our own. Nobody helped us - we did it ourselves.