1.Thisis___songIhavetoldyouabout.Isn'tit__beautifulone?A.thetheB.theaC.athe
2.AtthattimeAlanwas__one-year-oldbabyA.anB.a
3.Ithinkitis__usefuladviceA.aB./C.an
4.__Biologyis__scienceof__life.A./thetheB/the/C.The/