When the old man was alive,he ____ sit for hours at the door.A.would B.could C.must D.might为什么不选B?选哪个,为什么
问题描述：
When the old man was alive,he ____ sit for hours at the door.
A.would B.could C.must D.might
为什么不选B?选哪个,为什么
答
虚拟语气，选A
答
a吧。就跟if i were you, i would......一样。
答
c 表示肯定的意思
答
A
但是如果还有下文，B,C,D 都可以，文法上是没错的
答
没错,c讲的通,must表推测.