—Tim, our foreign teacher Ms. Green will go back to England next week.
—Really? Let's have a party to say goodbye to her ______ she is free this weekend.
句意：——蒂姆，我们的外教老师格林小姐下周要回英国了。——真的吗? 如果她这个周末有空的话，让我们举行一个聚会来向她告别吧。
考查从属连词的辨析。unless除非；if如果；though虽然。根据句意可知，“she is free this weekend”是“have a party to say goodbye to her”的假设条件，这里是if引导的条件状语从句，故选B。
—Tim, our foreign teacher Ms. Green will go back to England next week.
—Really? Let's have a party to say goodbye to her ______ she is free this weekend.
______ you keep moving, you'll never reach the top of the mountain.
—Do you know the traffic rules?
—Sure, one of them is that we can’t go across the street _____ the light is green.
I waited ______ they finished talking.
Get up early, ______ you will miss your train.
Nobody can hear you ______you speak in a louder voice.
—I think I am the shyest in my class. What should I do?
—Be more active in class, ________ you can improve your ability to express yourself.
—Mary doesn’t like fish chicken
—Ben doesn’t like fish, he likes chicken very much.
The Chinese doctors went to Italy to help the patients________they knew it was dangerous.
_____ Jane_____ her brother is going to the movies this weekend. One of them has to stay at home to look after their sick mother.
