Given a passage with a question and an answer to that question, classify if the answer actually answers the question into 'yes' or 'no'. Output 'yes' if the answer answers the question and output 'no' if the answer does not answer the question.

[EX Q]: Question: Do expanded effector memory T-lymphocytes in DBA/2 mice inhibit the growth of SL2 tumours?
Answer: SL2 tumours induce expansion of effector memory lymphocytes in DBA/2 mice. However, expanded effector memory lymphocytes do not inhibit the growth of tumours.
[EX A]: no

[EX Q]: Question: Are longer durations of antitumour necrosis factor treatment associated with reduced risk of cardiovascular events in patients with rheumatoid arthritis?
Answer: Anti-TNF therapy was associated with a significantly lower risk of cardiovascular events among patients with RA, older patients with RA and patients without prior exposure to methotrexate.
[EX A]: yes

[EX Q]: Question: Is fluoxetine effective in the treatment of post-stroke fatigue : a double-blind , placebo-controlled study?
Answer: Fluoxetine does not improve PoSF, although some concomitant emotional disturbances improved significantly. Our results suggest that PoSF may be associated with diverse etiologies but not closely related to serotonergic dysfunction. Further studies are required to elucidate the causative factors and to find an appropriate treatment for PoSF.
[EX A]:
no