Tags are very common in spoken English, and have many functions. One of the common functions is to start a conversation or help keep it going. The two basic rules about tag questions are:1  If the statement is negative, the tag must be positive.ags are very common in spoken English, and have many functions. One of the common functions is to start a conversation or help keep it going. The two basic rules about tag questions are:
The average cost for a community to fluoridate its water is estimated to range from approximately $0.50 a year per person in large communities to approximately $3.00 a year per person in small communities. For most cities, every $1 invested in water fluoridation saves $38 in dental treatment costs.55 âFor most cities, every $1 invested in water fluoridation saves $38 in dental treatment costs.â It can be calculated from these data that the average lifetime cost per person to fluoridate a water system is less than the cost of one dental filling.
Costs of water fluoridation to municipalities. z Region states that fluoridation costs are 60 cents per person per year. z In 2004: âcosts are about $3.00 per capita per annumâ Chief Dental Officer for Health Canada, January 2004 z Due to shortage of fluoridation chemicals, their costs are rising.osts to ordinary citizens who cannotconsume fluoridated public water, due to health concerns. 1. Purchasing water that is adequately filtered. 2. Purchasing expensive reverse osmosis or distillation equipment, [$2 - 4,000 plus $500/year for replacement filters].