Corss-cultural research and application of politeness language 并列题名：Corss-cultural research and application of politeness language Clinical research and application of stem cells Programming and application of the C language 并列题名：Clinical research and application of stem cells 并列题名：Programming and application of the C language Marketing research and application of statistical analysis research and application of vetiver grass 神奇牧草：香根草研究与应用：research and application of vetiver grass Arbuscular mycorrhizal research and application of horticultural plants