How to keep teens from drinking at a party where alcohol is served<br>Determine whether or not it is necessary to serve alcohol at the party. Depending on the type of party or the people there, serving alcohol may not the best choice. Try to gauge how many teens will be at the party, and the likelihood of underage drinking.
If you are going to have alcohol at a party where teens are present, it is advisable to calculate the amount of teens that will be present, and in turn, how likely underage drinking is to occur. 
( z1 advise :ARG2 ( z2 calculate :ARG0 ( z3 you ) :ARG1 ( z4 and :op ( z5 amount :quant-of ( z6 teen :ARG1-of ( z7 present ) ) ) :op ( z8 thing :degree-of ( z9 likely :ARG1 ( z10 drink :mod ( z11 underage ) ) :mod ( z12 in-turn ) ) ) ) ) )