问题补充:
Look! They soccer the playground.
A. play; on
B. are playing; in
C. playing; in
D. are playing; on
答案:
A. play; on
(答案→)B. are playing; in
C. playing; in
D. are playing; on
解析:句意:看!他们正在操场上踢足球。根据look可知此处用现在进行时be doing,故排除AC两项。on the playground在操场上,故选B。