More teenagers smoke today than at any【C1】______ since the 1970s, a federal study shows. Overall. 35% of children in grades 9-12 smoke cigarettes, a greater【C2】______ than 25% of adults who smoke.【C3】______ it is illegal to buy cigarettes until age 18. more than 75% of kids who【C4】______ them in stores are not asked for proof of【C5】______ , and they get cigarettes just as adults do: they walk in and buy them,【C6】______ no one checks their age. At a high school【C7】______ inaugurated a smoke-free campus this year, students who smoke cigarettes between classes【C8】______ that stricter laws will cut【C9】______ . Sixth and seventh-graders 【C10】 ______ at a middle school say they have little trouble【C11】______ stores to sell them cigarettes,【C12】______ unsupervised vending machines or getting【C13】______ students to buy cigarettes for them. They say they have【C14】______ the most successful store-buying line early: 'My【C15】______ is waiting in the car.' 【C16】______ smoking becomes less popular in adults, smoking becomes a form. of rebellion. Too often the rebellion leads to the tragic consequences of a【C17】______ smoking habit. Health experts warn that【C18】______ teen smokers quit soon, advances made in reducing lung and heart disease in the past 20 years will be【C19】______ . This will have a dramatic effect on the nation's【C20】______ . 【C1】