—Does Liu Hui serve in the army?—No,but he _____in the army for three years.A.served B.has servedC.is serving D.would serve

—Does Liu Hui serve in the army?—No,but he _____in the army for three years.A.served B.has servedC.is serving D.would serve
—Does Liu Hui serve in the army?
—No,but he _____in the army for three years.
A.served B.has served
C.is serving D.would serve

—Does Liu Hui serve in the army?—No,but he _____in the army for three years.A.served B.has servedC.is serving D.would serve
a,动作已完成
A:He has lived in Beijing for 8 years .
B:He lived in Beijing for 8 years .
分析：他在北京住了 8 年.（ A ）句讲的是到目前为止他在北京住了 8 年,可能还会继续在北京住下去.（ B ）句讲的是他在北京住过 8 年,现在已经不在北京了.
并不是用for就一定是完成时态.要参考语意.

B

B
现在完成时嘛，标志词‘for’