【题目】Tom, you play football in the street.
—Sorry. I do it again.
A.needn't; won't
B.mustn't; won't
C.won't; can't

【答案】B
【解析】考查情态动词。句意：汤姆，你禁止在街上踢足球。——抱歉，我以后不那样做了。表示禁止做某事，用mustn't表示禁止做某事；表示以后不再做，用一般将来时，所以答案是B。