Definition Cyanosis refers to bluish(带蓝色的 带青色的) color of the skin and mucous membranes resulting from an increased quantity of reduced hemoglobin(亚铁血 红蛋白;还原血红蛋白),orof hemoglobin derivatives, in the small blood vessels of those areas. It is usually most marked in the lips, nail beds(甲床),ears, and malar (颧骨的;颊的) eminences

Dummy variables (also indicator variables; binary variables categorical variables; dichotomous variables.) Qualitative variables in regression model For example: sex, race, color, religion, nationalit y, marital status, etc

Across 1. A metal used in batteries but not pencils 2. This element is found in the most odorous compounds 3. Its aqueous 2+ ion has a characteristic blue color 4. Bananas are rich in its cation 5. The noble gas with the second-lowest densi 6. Its hydride is the most common basic gas