第22题: [单项选择]The last half of the 19th century _________ the steady improvement in the means of travel. A. was witnessed B. has witnessed C. witnessed D. is witnessed 参考答案:C 答案解析:[妙翻巧译] 19世纪的后半叶,旅游方式取得了稳步的发展。 [解析] 根据主语the last half of the 19th century可以判断时间为过去时,主语和谓语witness(亲