If the computer should within the first three years we would repair it at our expense.A.

问题补充：

If the computer should within the first three years, we would repair it at our expense.

A. break up

B. break down

C. break off

D. break out

答案：

A. break up

(答案→)B. break down

C. break off

D. break out

解析：考查动词短语辨析。句意：如果电脑前三年内出故障，我们将免费维修。A分列，拆分，解散，放假；B出毛病，分解，感情失控；C断开，突然中止，结束；D爆发。故选B。