【简答题】已知抛物线的顶点在坐标原点,焦点为F(1,0),点P是点F关于y轴的对称点,过点P的直线交抛物线于A,B两点. (1)试问在x轴上是否存在不同于点P的一点T,使得TA,TB与x轴所在的直线所成的锐角相等,若存在,求出定点T的坐标,若不存在说明理由. (2)若△AOB的面积为 5 2 ,求向量 OA , OB 的夹角.
【判断题】学前儿童缺乏独立的自我评价能力,在很大程度上依赖成人的评价。
【单选题】疑似牛副结核病病料涂片镜检常用的染色方法是:()(627)
【简答题】设函数y=f(x),在函数图像上任取一点P(a,f(a)),写出点P关于y轴的对称点的坐标与关于原点O的对称点的坐标。
【单选题】点 P(a,f(a)) 关于 y 轴对称的点的坐标为()
【单选题】患者女,60岁。确诊为急性呼吸窘迫综合征,给予面罩吸氧.为了使吸入氧浓度能够达到55%,需将氧流量调至
【单选题】Which of the statements below is not true?
A.
Public health microbiology is closely related to food and dairy microbiology.
B.
About 1/3 of these have been awarded to scientists working on biological problems in the 20 th century.
C.
An applied microbiologist must be familiar with basic microbiology.
D.
Agricultural microbiologists try to decrease the loss caused by plant pathogens.
【判断题】Food microbiologists are concerned with not only food spoilage caused by microbial but also its useful function.
【单选题】点 P(a,f(a)) 关于 y 轴的对称点的坐标为 ( )
【单选题】疑似牛副结核病病料涂片镜检常用的染色方法是(2013 真题上133)