【题目】John was dismissed last week because of his ________attitude towards his job. （ ）
A.informal
B.casual
C.tough
D.violent

【答案】B
【解析】A．informal非正式的；B．casual随意的，随便的；C．tough强硬的，艰苦的； D．violent暴力的；句意：约翰上周被开除是因为他对待工作的态度太随便。根据句意，故选B。