Question

Yo busco la maleta perdida. Yo ________ (2 palabras) la maleta perdida.

Answer 1

Well, given that the blank requires 2 words (dos palabras), it cannot be encuentre. We need something which has the same meaning as busco (to look for), which is estoy buscando.
Yo estoy buscando la maleta perdida means the same as Yo busco la maleta perdida. Both of these sentences mean - I'm looking for the lost luggage. 

Answer 2

I think think the answer that goes in the blank above is encurentre.