A:②③④⑥⑦
B:①②⑤
C:②⑦⑧
D:①⑤⑨
患心绞痛的病人,可服下列哪种药
There are lots of storybooks the students.
已知两数的差与这两数的商都等于9,那么,这两个数的和是____ .