【单选题】The process during which liquid containing a reasonable amount of sensible heat at a particular pressure immediately changes into steam after admitted to a chamber at a lower pressure is called _____.
【简答题】(本小题满分12分). 如图,已知某椭圆的焦点是 F 1 (-4,0)、 F 2 (4,0),过点 F 2 并垂直于 x 轴的直线与椭圆的一个交点为 B ,且| F 1 B |+| F 2 B |=10,椭圆上不同的两点 A ( x 1 , y 1 ), C ( x 2 , y 2 )满足条件:| F 2 A |、| F 2 B |、| F 2 C |成等差数列. (1)求该弦椭圆的方程; (2)...