问题
选择题
(2014·东北三省三校一联)Traffic conditions in Beijing________for decades.At first people only complained about jams during rush hours，but today every hour is rush hour.
A．is worsening
B．have worsened
C．have been worsening
D．worsened
答案
答案：C
考查动词的时态。由空后的for decades可推知，此处要用完成时态，故可以排除A、D两项。由下句内容可知，北京这种交通状况是从过去一直持续到现在，且会持续下去，故应该用进行时态。
答案： C