问题
选择题
________ 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
A 考察连词。句义：既然你要做这份工作，就尽力去做。Since既然，while然而；unless除非；though尽管；根据句义说明A正确。