____Shall we play in the playground?
____Can I learn to use the computer?
____Would you like to come here?
____What would you like for your birthday?
A. Sure.
B. Yes, I'd love to.
C. OK, let's go.
D. It's a secret.
总条数
50
45
60
48
10
30
42
38
15
标记数
2
1
3
0
53
36
27
34
43
26
18
22
2 5
47
椭圆x225-y29=1上一点M到焦点F1的距离为2,N是MF1的中点.则|ON|等于( )