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.

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.

A: no
****
Q: Question: Is tumor differentiation a risk factor for lymph node metastasis in elderly patients with early gastric cancer?
Answer: Elderly patients with undifferentiated type histology early gastric cancer without other risk factors for lymph node metastasis may be candidates for endoscopic resection.

A: no
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Q: Question: Does biochar-amended potting medium reduce the susceptibility of rice to root-knot nematode infections?
Answer: These results suggest that biochar amendments protect rice plants challenged by nematodes. This priming effect partially depends on the ET signaling pathway and enhanced H2O2 accumulation.

A:
yes
****