you have to do the job you should try your best to do it well even though it may be very

问题补充：

you have to do the job, you should try your best to do it well even though it may be very difficult for you.

A. Since

B. While

C. Unless

D. Though

答案：

(答案→)A. Since

B. While

C. Unless

D. Though

解析：A.Since既然 B. While当…时候 C. Unless 除非 D. Though尽管；句意：既然你必须做这份工作，你就应该尽最大的努力把它做好，即使对你来说很困难。故选A