3) I bought a new computer. It cost me a lot of money. (which)

….................................................................................................

4) The man is a doctor. He lives next door to us. (who)

…..…………………..…………..................................................

5) I have a class. It begins at 8.00a.m. (which)

….................................................................................................

6) The person lives next to me. You saw him last night. (whom)

…..…………………..………….......................................................

7) They went on a picnic last Saturday. The weather was not fine. (even though) ……………………………………………………….

………………………………………………………………………

8) I don’t know the man. He is talking to Miss Lan. (who)

3) I bought a new computer. It cost me a lot of money. (which)

=>I bought a new computer WHICH cost me a lot of money.

ĐẠI TỪ QUAN HỆ :Làm chủ ngữ , thay thế cho danh từ chỉ vật.

….N (CHỈ VẬT) + WHICH + V + O...

4) The man is a doctor. He lives next door to us. (who)

=>The man WHO lives next door to us is a doctor.

ĐẠI TỪ QUAN HỆ :Làm chủ ngữ  thay thế cho danh từ chỉ người.

….. N (CHỈ NGƯỜI) + WHO + V + O

5) I have a class. It begins at 8.00a.m. (which)

=>I have a class WHICH begins at 8.00a.m.

ĐẠI TỪ QUAN HỆ :Làm chủ ngữ , thay thế cho danh từ chỉ vật.

….N (CHỈ VẬT) + WHICH + V + O...

6) The person lives next to me. You saw him last night. (whom)

=>The person WHOM you saw him last night lives next to me.

ĐẠI TỪ QUAN HỆ :Làm tân ngữ, thay thế cho danh từ chỉ người.

…..N (CHỈ NGƯỜI) + WHOM + S + V

7) They went on a picnic last Saturday. The weather was not fine. (even though) 

=>EVEN THOUGH the weather was not fine, they went on a picnic last Saturday.

OR: They went on a picnic last Saturday EVEN THOUGH the weather was not fine.

EVEN THOUGH/ ALTHOUGH + S+V.., S+V...: MẶC DÙ...

8) I don’t know the man. He is talking to Miss Lan. (who)

=>I don’t know the man WHO is talking to Miss Lan.

ĐẠI TỪ QUAN HỆ :Làm chủ ngữ  thay thế cho danh từ chỉ người.

….. N (CHỈ NGƯỜI) + WHO + V + O

Mong câu trả lời của mình sẽ giúp ích cho bạn nhé!!
Nếu có chút sai sót mong bạn bỏ qua giúp mình nhé T^T!
GOOD LUCK TO YOU!!!