Correct the following statements by changing the first/ last word only :

1. BCG is a kind of vaccine used to prevent Pneumonia.
2. Streptomycin is a kind of vaccine.
3. Breathing is a bio-chemical process.
4. The amount of oxygen in expired air is 21%.
5. The front opening of the trachea is guarded by a muscular flap called diaphragm.

1. BCG is a kind of vaccine used to prevent Tuberculosis.
2. Streptomycin is a kind of antibiotic.
3. Respiration is a bio-chemical process.
4. The amount of oxygen in expired air is 16%.
5. The front opening of the trachea is guarded by a muscular flap called epiglottis.