Such slipperiness, he says, can add an extra charge to a piece of theatre.
This will add an extra charge to your monthly bill for placing calls, exchanging texts and using data in another country - usually between $50 and $100 per month.
Think about offering this service only with advance booking and adding an extra charge, or you can rotate your staff so that your salon is open during times it usually would not be.
Now a U.S. lab has added an extra kick with electrically charged rings that could clear out smoke-filled hallways for firefighters, or deliver clingy shots of tear gas or pepper spray without the need for accuracy.
The recession added an extra kick.
The city recently added an extra "toxicity charge" of $14 per day — on top of the $16 — for older polluting vehicles in the congestion zone, at the urging of Sadiq Khan, the mayor of London.
Ice-walking adds an extra thrill.
Mr Sarkozy, too, has put up taxes and social charges and added an extra 4% surcharge on the super-rich, as well as bringing in an "exit tax" to stop French exiles cashing in capital gains in more favourable places.
The aspartate on position 260, a conserved asparagine spot, may affect both the interaction with the ISP (protein recognition event) and other electron transfer events, as it adds an extra negative charge to this interface.
But up to now, the DoH has only sought to reclaim the actual costs, without adding any extra charges.
(For an extra charge, diners can add one of eight sauces, from béarnaise to barbecue).
