Question

The wood was so rotten that when we pulled, it _________ into fragments．

1. A.
   broke away
2. B.
   broke off
3. C.
   broke up
4. D.
   broke through

Answer 1

C
break up意为“打碎、破裂、分裂”，本句意为“木头已经是如此的腐朽以至于我们一拉它就变成了碎片”。break away意为“逃跑”，尤指“突然的”行为；break off意为“中止”，也含“突然”之意，有及物和不及物两种用法；break through意为“穿越”。此外，break through还有在科技上取得进展之意。