I

1. She was upset because he didn't come.

2. She always gets bad marks so her mother is angry.

II

1. She is old so she can't work hard.

2. I felt tired so I went to bed

3. I feel asleep becasue the story is boring.

4. The weather was cold so they had to cancel their picnic.

5. They passed the exam because they studied hard.

*Giải thích:

→ because + S + V: Bởi vì ... (giải thích cho mệnh đề trước)

→ ... so + S + V: Cho nên ... (Diễn tả kết quả của mệnh đề trước)

I/ Adverb clauses of result

1 He didn't come;therefore, she was upset

2 She always gets bad marks;therefore; her mother is angry 

Cấu trúc:
S + V. As the result/ Therefore, + S + V

II/ Rewrite ( SO <-> BECAUSE)

1 She is very old so She can't work hard

2 I felt tired so I went to bed early

3 I feel asleep because the story is boring

4 The weather was cold so they had to cancel their picnic

5 They passed the exam because they studied hard

Cấu trúc

→Because + S1 + V1,S2 + V2 hoặc S1 + V1 + because + S2 + V2 

→S1 + V1,+ so + S2 + V2

→Lưu ý :Because dùng để chỉ nguyên nhân và so dùng để chỉ kết quả