问题
选择题
______ the project in time, the staff were working at weekends.
A．Competing
B．Having completed
C．To have completed
D．To complete
答案
D
to complete the project in time为动词不定式作目的状语。A表示正在进行；B表示该动作发生在主句谓语之前；C常用在某些固定句式中。