what ______foerest in our country in the ;ast ten years.A.has happened do B.is happened toC.has happened at D.is happening 但是结构是be happened to sb.难道说对物就该是be happened at sth.是这样的吗?是不是也可以说what has happened in the office

最佳答案应该是：has happened to
若选项里没有has happened to,那当然只能选C了。理由如下：
首先，“in the last+一段时间”用于现在完成时[have/has+过去分词]，所以排除B,D
其次，happened do很显然是错误的，所以排除A
另外，“what happened at the forest”可理解成 at跟the forest搭配，即“at the forest在森林”

没有be happened at
做发生讲的时候，主语是所发生的事情，说某人或某事发生什么事情时，该人或事前要用介词to
人做主语时，后接不定式或on

答案选B,只有to才可以和happen搭配
可以说what has happened in the office

A what has happened to

happen vi.发生, 碰巧, 偶然
v.发生, 恰巧, 偶然发现
happen to sb.(or sth.)某人(或某物)发生...
这里的has happened at 里的at 是 at foerest (在森林方面).
句意:过去十年我国的森林发生了什么情况?
当然可以说what has happened in the office,意思是"在办公室发生了什么事",办公室本身不可能发生什么事,所以不能用what has happened to .上句亦是如此.