Question

Read these two sentences:

Answer 1

The research suggests we may have little time left to help the big cats of the world.

However

Our progress in all major habitats has been very encouraging.

Answer 2

Answer:

The correct option is HOWEVER.

Explanation:

The most suitable transition word to link the two sentences is HOWEVER.

HOWEVER in this context is used to join two opposite ideas. We could paraphrase them by saying that "even though our progress in all major habitats has been very encouraging, it will impossible for us to help the big cats of the world".