9.They were greatly amazed to find the city______ a lot in the past ten years.A. changeB. changedC. to have changedD. changing不明白为什么选B ,C不行吗?

9.They were greatly amazed to find the city______ a lot in the past ten years.A. changeB. changedC. to have changedD. changing不明白为什么选B ,C不行吗?
9.They were greatly amazed to find the city______ a lot in the past ten years.
A. change
B. changed
C. to have changed
D. changing
不明白为什么选B ,C不行吗?

9.They were greatly amazed to find the city______ a lot in the past ten years.A. changeB. changedC. to have changedD. changing不明白为什么选B ,C不行吗?
选B
但是这里的changed不是过去式,而是一个过去分词.做宾语补足语.
表示宾语the city与变化之间的被动关系.
再如:
I found a baby crying there 主动关系用现在分词
I found a baby tied to a bed 被动用过去分词

were greatly amazed 主句是过去时态
find the city(that) changed a lot in the past ten years从句必须是过去时态
从句中省略了主语

in the past ten years 是过去,要用过去式

他们惊讶的发现在过去的十年里城市发生了很大的变化。
这里城市发生变化，这个改变change是被改变be changed，是被动语态，城市不是自己发生变化的，是人在改变城市，城市是被改变的。
但是C不是被动。而B其实就是be changed，find something done~