题干
She has two daughters, ____ are nurses.
A：all of them
B：both of them
C：both of whom
D：all of whom
答案(点此获取答案解析）
C
A：all of them
B：both of them
C：both of whom
D：all of whom
2C(g)＋D(g)；△H＜0。现将1 mol A和2 mol B加入甲容器中，将4 mol C和2 mol D加入乙容器中，此时控制活塞P，使乙的容积为甲的2倍，t1时两容器内均达到平衡状态(如图1所示，隔板K不能移动)。下列说法正确的是（ ）
