下面是一段初中英语课堂实录片段。阅读后回答下列四个问题: 教学片段: Teacher: Hello, everyone, today we're going to learn the Present Perfect. What is the Present Perfect? The Present Perfect is a grammatical combination of the present tense and the perfect aspect, used to express a past event that has present consequences. For example: I have already finished my homework. She has worked out a plan. As you can see, the Present Perfect is made up of two parts: have+past principle(done)... (Then the teacher began to illustrate different usages of the Present Perfect.)