To answer the first part of your question, I'd like to say that our studies were very extensive.
你问题的第一部分,我要说的就是我们的研究非常广泛。
Dan wondered why he was wanted by the police, but he went to the station yesterday and now he is not worried anymore.
丹奇怪警察为什么找他,但昨天还是去了,结果他一再担心了。