在单因素方差分析中，若检验多个总体均值是否相等，其基本假设条件不包括以下哪项？

马克思主义之所以能够保持其生命力和创造力，主要是因为：

In reading comprehension, what does 'inference' refer to?

当车辆接近人行横道线时，以下哪种行为是正确的？

Given the sentence 'His refusal was worded in such a graceful manner that it did not offend anyone.', what is the intended meaning of the word 'graceful' in this context?