求翻译：主要从留守老人的生存现状及其生活面临的困难，如农村留守老人的收入来源、收入水平、农村留守老人的健康自我评价、农村留守老人的养老资源等方面进行研究。是什么意思？

The main difficulties faced by the survival status of the elderly left behind their lives, such as the source of income of the elderly left behind in rural areas, income levels, the health of the elderly left behind in rural areas of self-evaluation, the pension resources of the elderly left behind

From the main left-behind old survival status quo and its life difficulties faced by rural areas, such as the income of the elderly left behind, left-behind rural income levels, the health of elderly people left behind self-evaluation, the rural areas of the elderly in nursing homes, and other resou

Mainly from remains behind to take care of things the difficulty which old person's survival present situation and the life faces, like the countryside remains behind to take care of things old person's source of income, the income level, the countryside remains behind to take care of things old per

Mainly from the left in the old man's living situation and their difficulties in life, such as sources of income of the rural elderly, income level, health self-judgment of the rural elderly, rural Endowment resources for the elderly and other aspects of research.

正在翻译，请等待...