it
it is difficult 后面为什么不是doing？
is difficult 后面为什么不是doing？
1，it is difficult后面可以是动词不定to do，也可以是(in ) doing。但两者语义不同。
2，Ⅰts difficult to do. 作为一个完整句子，这个才是正确的。
意思为:做…是困难的。
It is difficult to do 是一个句型，其中 it 是形式主语，不定式 to do 是句子的真正主语。
如：Its difficult to learn English.
学英语是困难的。
it difficul to do 则只是一个结构，该结构前面一般都有一个及物动词如 think, believe, find, make 或者 consider 等等。其中 it 一般视为形式宾语，形容词 difficult 是宾语补足语，不定式 to do 则是真正的宾语。
如：I think it difficult to learn English.
我认为学习英语是困难的。
3，而It`s difficult (in) doing sth.
是做某事有困难。
It is difficuit studying English to me.
对我而言，学英语是有困难的。
in a difficult situation是什么意思？
in a difficult situation
在困难的情况下、处于困境
短语
especially in a difficult situation 坚持
be in a difficult situation 处于艰难境地
He is in a difficult situation. 他处境困难。
例句:
1. I think that we are in a difficult situation but maybe lets not panic about it.
我认为我们正处于一个困难时期,但是也许我们不用为此而恐慌。
2. They need to receive enough serious practice that theyll hopefully act fast in a difficult situation.
他们需要非常严肃的训练这样才有希望在困难的情形下迅速做出反应。
3. Those two factors put many developing countries in a difficult situation.
这两方面的因素使许多发展中国家处于困难的境地。
4. Im in a difficult situation and I dont know what to do.
我处在一个困难的情形中，而我也不知道该怎么办。