同样是during引导的时间状语 主句的时态咋就不一样呢

题目

同样是during引导的时间状语 主句的时态咋就不一样呢
【2013浙江10.During the last three decades,the number of people participating in physical fitness programs ______ sharply.
A.was increasing B.has increased C.had increased D.will be increasing
27【答案B
【解析考查动词时态.根据时态标志词during the last three decades,可知使用现在完成时态,选B.
during the period of recent terrorist activities,people____not to touch any unattended bag
A.had always been warned B.were always being warned C.are always warning D.always warned 为什么选B,

答案

27,选has increased 是正确的,因为during the last three decades,在过去的30年里（包含了今年）.这是很明显的现在完成时的时间状语.the number 是数字,要用单数谓语动词.下面一题选B：根据during the period of rec...