第23题: [单项选择]He worked ______ at his task for weeks before he felt satisfied that the results would justify his long effort. A. occasionally B. regularly C. patiently D. assiduously 参考答案:D 答案解析:(assiduously坚持不懈地,刻苦地)。句意为:他连续好几个星期坚持不懈地执行任务才觉得满意,因为结果表明他长时间的努力是值得的。A.occasionally偶尔;B. regularly定期地