A．单句填空
1．The best moment for the football star was ________he scored the winning goal.
答案 when [句意：对这个足球明星来说，进球得分的时刻是最好的时刻。when在表语从句中表时间。]
2．“Every time you eat a sweet, drink green tea.”This is ________my mother used to tell me.
答案 what [句意：“每次你吃甜东西，喝点绿茶。”这是过去妈妈经常对我说的话。分析结构可知，此处考查的是表语从句的引导词。从句缺少tell的直接宾语，用what引导。]
3．—What a mess! You are always so lazy!
—I'm not to blame, mum. I am________you have made me.
答案 what [句意：——真是一团糟！你总是这么懒惰！——妈妈，别怪我。我现在这样就是你造就的呀。分析成分可知，I am后是表语从句，引导词what在从句中作made me后的宾语补足语，相当于the one that，即I am the one that you have made me。类似例子还有：He is no longer what(＝the one that) he used to be。]
4．Grandma pointed to the hospital and said, “That's________I was born.”
答案 where [句意：奶奶指着那个医院说：“那就是我出生的地方。”此处考查的是名词性从句中的表语从句。]
5．Courage is a kind of quality ——and that's ________it takes to face the challenges in life.
答案 what [句意：勇气是一种好品质，那就是面对生活中挑战所需要的品质。that's 后为表语从句，而且引导词作从句中takes的宾语。故应填what。]
6．Faced with difficulties, you should believe your confidence is ________makes a difference.
答案 what [句意：面对困难，你应该相信你的自信会起很大作用。make a difference意为“起作用，有影响”；本句中“________makes a difference”是表语从句，因为从句缺主语，故用what。]
7．Don't be sad. The most important thing is ________we must learn from our mistakes and move on.
答案 that [句意：不要难过，最重要的是我们必须从错误中吸取教训，并继续前进。表语从句不缺任何成分，故填that。]
8．I'm afraid he is more of a talker than a doer, which is ________he never finishes anything.
答案 why [句意：我觉得他说得多做得少，这就是他从来没有完成任何事情的原因。分析句子结构可知，此处which引导非限制性定语从句，指代前面整个句子的内容；在定语从句中，空处引导表语从句，再结合句意可知应填why。]
9．The message of Saving Private Ryan is ________humans want peace, not war.
答案 that [句意：《拯救大兵瑞恩》传达的信息是人们想要和平而不是战争。此处为表语从句，从句不缺少成分，所以用that引导。]
B．单句改错
1．From space, the earth looks blue. This is why about seventyone percent of its surface is covered by water.
________________________________________________________
答案 why→because [句意：从太空看，地球是蓝色的。这是因为地球表面大约有71%的区域被水覆盖。分析句子结构可知，此处为表语从句，表示原因，故用because。because后加原因，why后加结果。因此把why改为because。]
2．Evidence has been found through years of study why children's early sleeping problems are likely to continue when they grow up.
________________________________________________________
答案 why→that [句意：通过数年的研究，儿童早期睡眠问题长大后有可能继续的证据已经被找到了。分析句子结构可知，空格后面的部分是解释说明evidence的内容，是evidence的同位语从句，引导词在从句中不作任何成分，故把why改为that。]
3．Her only problem, if you can call it a problem, is what she expects to be successful all the time.
________________________________________________________
答案 what→that [句意：如果能称之为问题的话，她唯一的问题是她一直想成功。引导表语从句，从句中不缺少任何成分，故用that引导。]
4．The problem is what we can improve our reading skill in such a short time.
________________________________________________________
答案 what→how [句意：问题是我们如何在这么短的时间内提高我们的阅读技能。分析句子成分并结合句意可知，这里需要用连接副词how来引导表语从句。]
5．There is still some doubt that the system will work even though all the factors have been considered.
________________________________________________________
答案 that→whether [句意：即使所有的因素都考虑了，系统是否会运转仍有些疑问。whether引导同位语从句，作doubt的同位语，whether表示“是否”。]
6．People all over the world have a dream whether they will always live a peaceful life.
________________________________________________________
答案 whether→that [句意：全世界的人民都有一个梦想，即永远过着和平的生活。此处为同位语从句，解释名词dream的内容，因为从句中不缺少成分且意义完整，所以用that引导。]
7．The expert's argument what the increasing number of cars is the main cause of the rising PM 2.5 readings has got much support from the public.
________________________________________________________
答案 what→that [句意：这个专家的争论已经得到了来自公众的大力支持，争论围绕汽车数量的增加是PM2.5值上升的主要原因。此处为同位语从句，解释说明argument的内容，因从句不缺少成分，且句意完整，所以使用that引导。]
易错题一：名词性从句中连接词的误用
[例1] ________ surprised me most was to see some of the village people seated on the benches at the end of the room.
[错解] It/That/Who
[错因分析] 此处缺少主语，因此考生容易误用It, That, Who, Which等。
[答案] What
[心得体会]
[例2] I have no idea ________ he will come here or not this afternoon, for he is very busy at the present time.
[错解] which/that/if
[错因分析] 该题貌似定语从句，考生易误填which/that。此外，一些考生也许一看到后面的“or not”容易误填if。根据语意可知，idea后面接一个同位语从句，该从句是对idea的解释说明，且由后面的“or not”可知应用whether。if不能引导同位语从句。
[答案] whether
[心得体会]
易错题二：漏用关系词
[例] She was so angry and spoke so fast that none of us understood ________ ________
he said meant.
[错解] that; what
[错因分析] 许多同学一看便判断出understood后为宾语从句，第一空误填that; 第二个空认为said后缺宾语，填what。
[答案] what; what
[心得体会]
易错题三：名词性从句中用it作形式主语或宾语
[例] ________has been proved that eating vegetables in childhood helps to protect you against serious illnesses in later life.
[错解] What
[错因分析] 考生误认为此空引导主语从句，缺少主语，误填What。
[答案] It
[心得体会]