645._____ the project in time,the staff were working at weekends.
A.Completing
B.Having completed
C.To have completed
D.To complete
646.I like getting up early in summer.The morning air is so good _____.
A.to be breathed
B.to breathe
C.breathing
D.being breathed
645.答案是D;动词不定式表示目的。
646.答案是B;在主语+be+adj.+to do的结构中，动词不定式常用主动形式表示被动意义。
