阅读文章，了解其大意，然后选择正确选项填空。 mr green had to travel somewhere on business, and as he was in a hurry, he decided to go by air. he liked sitting (1) _____ a window when he was flying, so when he (2) _____ the plane, he looked for a window seat. he (3) _____ all of them taken except one. there was a young man seated beside it, and mr green was (4) _____ that he had not taken the one (5) _____ the window. so he went towards it. when he (6) _____ it, however, he saw that there was (7) _____ on it. written in large letters, (8) _____ “this seat is kept for proper balance. thank you.” mr green had (9) _____ seen such a notice before, but he thought the plane (10) _____ something very heavy in its room (11) _____ made it necessary to have the passengers properly (12) _____. so he walked on and found another empty seat, not
