The answer is on this website.
http://studyspanish.com/grammar/lessons/regverb1
Answer:gusta for first 3 gustan 4 then back to gusta and last gustan (Tho they aren't fully conjugated so I would double check)
Explanation: spanish soeaker
1: Panera
2. Cantaban
3: Jardinera
4: Ratonera
5: Llavera