Номер 3

1) loved

2) boring

3) sure

4) should

5) go

Номер 4

1) Znanija.com

2) Ask questions and answer other peoples questions.

3) It helps you out when you can’t do your homework yourself.

4) Sometimes people answer your questions incorrectly.

5) Make questions which were already answered by someone automatically solved and improve the API for the website.