"The host seated me next to Mrs. Smith"
1. -> see sit 2;3
2.尽心尽力(去做某事)
If yousit down and do something, you spend time and effort doing it in order to try to achieve something.
e.g. Have you both satdown and worked out a budget together?...
你们有没有同心协力制订出一份预算呢?
e.g. 150 countries satdown to discuss the impact of human activities on the atmosphere.
150 个国家共同认真讨论了人类活动对大气的影响。
3. see also: sit-down