问题补充:
Jack is often seen basketball with his friends after school.
A. play
B. to play
C. to playing
D. played
答案:
A. play
(答案→)B. to play
C. to playing
D. played
解析:本题的含义是经常看见Jack和朋友们在一起打篮球,是被动句,看到某人做某事,
在英文中可以说see sb doing或see sb do,在被动句中,后者do变成to do,
故本题只能选B。