从A、B、C、 D四个选项中，选出可以填入空白处的最佳选项.

1. ---I am sorry that I stepped on your foot!

　---Oh,________!

A. no problem　　　　　 B. pardon me　

C. you are wrong　　　　 D. think nothing of it

15. The DJ adjusted the beats of the music so as to be ____ the singing star’s voice.

A. in search of　　　　　　　　　　　　　　 B. in terms of

C. in harmony with　　　　　　　　　　　　 D. in touch with

14. Barack Obama, _______ we believe can perform successfully in international affairs, has to consider North Korea as a headache.

A. when　　　　　　 B. where　　　　　　 C. whom　　　　 D. who