Mark the option which shows another way to rewrite the cond...

Rosana Fisher works at an outdoor activities centre on the west coast of Scotland. She teaches mountain climbing, scuba diving and hang-gliding. She's talking to some young people who've just arrived at the centre:

I - 'You can't do any of the activities unless you're with an instructor.'

II - 'We won't let you start an activity if you don't have the correct equipment.'

III - 'You can't go scuba diving unless you've done the training course.'

IV - 'Remember you can't leave the centre unless you say where you're going.'

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