Beijingwasunderan“orange”smogalertonFeb.24,whichmarkst...
来源：语文精选馆 3.14W
问题详情：
Beijing was under an “orange” smog alert on Feb. 24, which marks the first time the second-highest warning level of a new system introduced last year .
A. raised B. has been raised C. rose D. has risen
【回答】
B
知识点：动词时态与语态
题型：选择题
