问题

You won’t work out the problem ______ you understand it. So listen to me explain now.
A:since
B:when
C:unless
D:though;
B:when
C:unless
D:though;
正确答案是:
同类题型
Jim can’t find pen. Can you lend to him
There ______ a football game in our city next week.
in road _____ for repairs, so we hadto change the route to the downtown
Only when the government increases affordable homes for low-income groups________.
Tony is said________ to New York,and now he is studying medicine in a famous college in America