Используется Perfect потому что это твой личный опыт, а если смущает слово before , то предложение переводиться просто как :я здесь уже был
1. people. 2.take. 3.visit. 4.plane. 5.do-educational.
1 What is he writing?
2 What is he doing?
3 Who is writing an article about Moscow?
4 What article is he writing?
5 Why should we keep silence?
1. When crossing (Participle I, обстоятельство) the street, first look to the left.
<span>1) Where did John study? 2) What did the teacher tell his pupils? 3) Why did the teacher ask John? 4) What did John answer? 5) What is your favourite season? 6) Why do you like it? </span>