15．_______ snacks and drinks, but they also brought cards for entertainment when they had a picnic in the forest．

A． Not only they brought　　　　　 　　　　　　 B． Not only did they bring

C． Not only brought they　　　　　 　　　　　　 D． Not only they did bring

14． Every day the boy, together with his classmates, _____ to go to the playground and ____ football, ____ themselves．

A． are noticed; play; enjoying　　　　 　　　　　　 B． is noticed; plays; enjoying

C． are noticed; plays; enjoys　　　　 　　　 　　　 D． is noticed; play; enjoying

13． ----Have you known Professor Jackson in our department for a long time ?

　 ----Yes, since he _____ the our university．

A． has come　　　　　 　 B． comes　　　　 　　　　　 C． had come　　　　　　　 D． came