一、1.instead2.allowed 3.licence 4.teenagers 5.silly
二、1.drive2.doing 3.to swim 4.to think 5.pierced6.wearing
三、1.should beasked 2.should be allowed 3.shouldbe finished 4.can be used
四、1.should beallowed 2.don't think; aren’t’tserious enough 3.seemed to 4.allow me to 5.spendtime with