we have finished the course, we shall start doing more revision work.
A. For
B. Ever since
C. Now that
D. By now
网友回答
A. For
B. Ever since
(答案→)C. Now that
D. By now
解析：考查连词：A. For因为，一般不放在句首，B. Ever since自从C. Now that既然D. By now到现在为止，句意：既然我们已经完成了课程，我们应该多做些复习工作。选C。