Professor Smith along with his assistants on the project day and night to meet the deadlin

问题补充：

Professor Smith，along with his assistants，on the project day and night to meet the deadline.

A. work

B. working

C. is working

D. are working

答案：

A. work

B. working

(答案→)C. is working

D. are working

解析：该句主语是Professor Smith，故谓语动词用单数。当together with，as well as，no less than，rather than，but，except，along with，like，besides，as much as，more than...连接两个主语时，谓语动词要与前面的主语保持一致。