A recent study found that many users spend up to 40 hours a week on the Internet; (3) ______ they felt guilty,Đoạn văn3/30A recent study found that many users spend up to 40 hours a week on the Internet; (3) ______ they felt guilty,although despite unless withoutGiải thíchĐáp án A Giải thích: although + mệnh đề: mặc dù