Animals, Antiviral Agents, Benzimidazoles, Chromosome Mapping, Cloning, Molecular, DNA, Complementary, Drug Resistance, Viral, Genotype, Giant Cells, Mice, Mice, Inbred BALB C, Molecular Sequence Data, Respiratory Syncytial Virus Infections, Respiratory Syncytial Viruses, Temperature, Viral Fusion Proteins, Viral Plaque Assay, Viral Proteins