the project in time, the staff have been working at weekends since last summer.
A. Completing
B. Having pleted
C. To have pleted
D. To plete
网友回答
A. Completing
B. Having pleted
C. To have pleted
(答案→)D. To plete
解析：考查非谓语动词。句意：为了及时完成这些工程，自从去年暑假以来全体员工一直在周末工作。不定式表示具体的将要进行的动作，其逻辑主语为句子主语，结合语境可知选D。