【1-1】   （2011*烟台） _______ you have tried it on, you can’t imagine how pretty the new style skirt is.
A. Because   B. Although         C.Unless         D. When
【1-2】   （2011*青岛） You will achieve nothing _  you work hard.
A. if                     B. unless               C. when       D. that
【1-3】   The art club is for members only. You can’t go in _______you are a member.
A.unless   B.because   C. if    D. though
【1-4】（2010·宁波）—May I surf the Internet now?
—No, ______you have finished doing the dishes.
A. if    B. unless   C.because   D. when
重点短语
1．be afraid to 害怕去做；不敢去做
【用法总结】
(1)be afraid to do sth. 与Be afraid of doing sth.
两者都表示“害怕”，“不敢”。
但强调“动作”上的不敢用to do.
强调担心“发生的结果”用of doing.
(2)I’m afraid(that)…用来有礼貌地表达可能令人不快的消息。
(3)回答别人的提问时，可用省略形式I’m afraid so(not).