试题题干
WORD FORMATION
Complete the following sentence with the proper form of the word in the bracket.
(robber) Acting on inside information, the police were able to arrest the gang before the 
occurred.
参考答案
试题解析
此处缺少名词。
occurred是谓语动词，前面缺少主语。但是robber是强盗的意思。强盗发生不符文意。根据句意可知应该是抢劫案发生，所以变robber为名词robbery。
句意：警方根据内幕消息，在抢劫发生前逮捕了那帮匪徒。