填空题
填空题
填空题圆心在Y轴上，且与直线χ+y-3=0及χ-y-1=0都相切的圆的方程为_____．
填空题若正三棱锥底面边长为a，且三条侧棱两两垂直，则它的体积为_____．
单选题
单选题 D You know what a hotel is, of course. perhaps, you also know what a condo is--a residential（居住的）building divided into separate unionist that are owned by different people. What you may not know is
单选题
单选题 C Many schools have their art programs removed in an effort to improve test scores money. However, some researchers believe that this is not correct. Students can some basic skills in art class that
单选题
单选题I chose this coat in the end because______ ones were all too expensive.
单选题
单选题C Many schools have their art programs removed in an effort to improve test scores money. However, some researchers believe that this is not correct. Students can some basic skills in art class that
单选题
单选题B Maria Mitchell（1818-1889）, the first woman astronomer（天文学家）in the United States, was born in Nantucket. Massachusetts. Her parents valued education insisted on giving her the same quality of educat
单选题下列函数在各定义域中为增函数的是（）
单选题
单选题B Maria Mitchell（1818-1889）, the first woman astronomer（天文学家）in the United States, was born in Nantucket. Massachusetts. Her parents valued education insisted on giving her the same quality of educat
单选题
单选题--Let’s go to the concert tonight. Mary. --Sorry. I______ .I have to help my mom with the housework.
单选题