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.
It depends on where you get the water. If you have a well, the water is free. If you live in an apartment, you don't pay for the water. The average cost for water for home use â¦ is $2 per 1000 gallons. That breaks down to 2 cents for 10 gallons.If you buy water from a store, the cost can vary widely. For example, a gallon of Great Bear mountain spring water can be bought for 89 cents in some places.f you live in an apartment, you don't pay for the water. The average cost for water for home use â¦ is $2 per 1000 gallons. That breaks down to 2 cents for 10 gallons. If you buy water from a store, the cost can vary widely.