问题补充:
you have worked out the first problem, you may go on to work on the second.
A. Even if
B. Unless
C. Now that
D. Though
答案:
A. Even if
B. Unless
(答案→)C. Now that
D. Though
解析:考查连词:A. Even if即使B. Unless除非C. Now that既然D. Though虽然,句意:既然你已经算出了第一个问题,你可以继续算第二个问题。选C。