Complete the second sentence so that it has the same meaning as the first

HELP MEEEEEE!!!!!! 
V. Complete the second sentence so that it has the same meaning as the first.

1: Trung has to do a lot of homework, so he can’t go out with us.

-> Because ____________________________________________________________

2: They built some new schools in this city.

-> Some new schools __________________________________________________________

3: She will revise the lesson carefully.

-> The lesson ___________________________________________________________.

4: You should work hard right now or you don’t pass the exam.

-> If you don’t_________________________________________________________________.