How do we start the problem? What is it asking?
Answer:
b,a,a,b
Lions look different from tigers, because one has stripes, and the other does not.
Lions as well as tigers are meat-eaters.
Both lions and tigers are dangerous animals.
Tajikistan is about 3,000 meters (9,800 feet) above sea level.
Kyrgyzstan's AVERAGE is 2,750 meters above sea level. It ranges from 7,439 meters (24,406 feet) all the way down to 1,500 meters (4,921 feet) above sea level.
Answer:
inside and outside addresses
formal salutations and closings
subject lines specific to the topic