题干
I asked him _____we had to go .He told me just two more miles
A：how much longer
B：how much farther
C：how long
D：how far
答案(点此获取答案解析）
B
A：how much longer
B：how much farther
C：how long
D：how far
的二次曲线,该曲线两焦点之间的距离为（ ）