问题补充:
He often tennis with his friends. Now they tennis at school.
A. play; play
B. plays; playing
C. plays; are playing
D. playing; are playing
答案:
A. play; play
B. plays; playing
(答案→)C. plays; are playing
D. playing; are playing
解析:第一空前有often经常,故应用一般现在时,主语是he,故谓动应用单数第三人称;第二空前有now,故应用现在进行时。故选C。