问题补充：
My brother usually his classroom after school. But now he basketball.
A. cleans; plays
B. is cleaning; plays
C. cleans; is playing
D. is cleaning; is playing
答案：
A. cleans; plays
B. is cleaning; plays
(答案→)C. cleans; is playing
D. is cleaning; is playing
解析：句意:我的哥哥通常在放学后打扫教室.但是现在他正在打篮球.结合语境可知前文描述的是经常性动作,故用一般现在时态.下文描述的是现在正在进行的动作,故用现在进行时态.故选C.
