----- Nội dung dịch tự động từ ảnh ----- 14. We (A) have studied (B) had studied (C) are going to study 15. We all morning. Let's take a break now. (D) were studying the movie several times before Kevin got here. (A) have watched (B) are watching (C) had watched (D) will watch 16. Peter (A) will stay D17. After Bob in Singapore since 2002. (B) has stayed (C) stayed his homework, he went to a movie with Cathy. (D) was going to stay (A) has done (B) does (C) had done (D) will do 18.A : have Sam worked on solving the air pollution in his country? B : For about ten years. (A) When (B) While (C) How often (D) How long D19.While I TV last night , Kelly a shower (A) watched ; took (B) had watched ; had taken (C) was watching ; was taking 20. When Sam got to the airport, he found the plane_ off'already. (A) has taken (B) took (D)have watched ; has taken (C) is taking (D) had taken