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。
He added that a student had dressed up as a policeman and was playing all sorts of silly jokes on people.
还对工人说,有个学生常装扮成警察无聊地同别人开玩笑。