1. Opera is when the performance has operatic voice, singing frequent vocal solos with a live orchestra. The libretto, or the dialogue of an opera, is completely set to music. A Light Opera incorporates spoken dialogue and is more appealing to a broad audience. It still has operatic voices and a live orchestra. Musical Theater is much less demanding and usually contains musical number interspersed with spoken dialogue. The signing actors are usually equipped with microphones and the music is recorded.
2. To achieve full range, it requires years of concentrated training and full physical maturity. Usually an opera singer doesn't reach peak performance until age thirty or older.
3. La Boheme, by Puccini, is basically about a love between a seamstress named Mimi and a poet named Rodolfo. They immediately fall in love but Roldofo soon wants to leave her because she is very flirtatious. Then, Mimi becomes very ill and Roldofo feels bad because their life together has worsened her health. At the end, they reunite just before Mimi dies.