中国近代第一个领导资产阶级革命的全国性政党同盟会所创办的机关报是（ ）

单项选择题According to a survey of American households, the probability that the residents own two cars if annual household income is over 50,000 and 70% had two cars. The probability that annual household income is over $50,000 if the residents of a household do not own two cars is ________.

单项选择题若不全为零，且,则下面等式成立的是（ ）。