我们的计划是我们一周去一次那里。
The question is whether they will support the plan. 问题是他们是否会支持这个计划。 (2)连接代词
引导表语从句的连接代词主要有：who，whom，whose，what，which，whoever，whatever，whichever等。
The problem is who we can get to replace her. 问题是我们能找到谁去替代她。 Tom is no longer what he used to be. 汤姆不再是以前的汤姆了。 (3)连接副词
引导表语从句的连接副词主要有：when，where，why，how，whenever，wherever，however等。
That was where we camped last time. 那就是我们上次野营的地方。
This is why Sara was late for class. 这就是Sara上课迟到的原因。 (4)其他连接词
另外，because，as if，as though，as，like等连接词也可引导表语从句。 He didn't have breakfast.That is because he got up late. 他没吃早饭，因为他起晚了。 2．注意事项
(1)reason作主语时的表语从句
主语为名词reason时，表语从句中的连接词要用that，而不用because。
The reason for such a serious accident is that the driver was too careless and drank too much.
这么严重的一起事故完全是司机太粗心、喝酒太多造成的。
(2)如果主句的主语是idea，advice，suggestion，order，request，requirement等名词时，表语从句的谓语动词要用虚拟语气，即“(should＋)动词原形”的形式。
His suggestion is that we should stay calm. 他的建议是我们应保持冷静。 (3)其他系动词＋表语从句
除be以外，可用于表语从句的系动词有：seem，look，appear，sound，taste，feel，remain等。
It looks as if it is going to rain. 看来要下雨了。
It sounds as if you are from the south of the United States. 听起来你好像来自美国南部。 [即时演练3] 单句语法填空
①My question is whether you are in favour of us. ②The fact is that you've lost a good chance. ③I got up late.That's why I was late for school. (四)同位语从句
用作同位语的从句，叫同位语从句。它一般跟在某些名词(如fact，idea，news，promise，information，message等)的后面，用以说明或解释前面的名词。
1．同位语从句的连接词
引导同位语从句的词有从属连词that(没有词义，不作成分，不能省略)，连接副词how，when，where等。
We must remember the fact that goats usually live in mountainous country. 我们得记住山羊通常生活在山区这一事实。
They usually write exact instructions how the music is to be played. 他们通常要为如何演奏音乐而写出精确的说明。 2．注意事项
(1)分隔式同位语从句：被与所解释说明的名词分隔开的同位语从句叫分隔式同位语从句。
A saying goes that practice makes perfect. 常言道，熟能生巧。
(2)表示建议、命令、要求等的名词(如suggestion，order，demand，command，request，advice等)后的同位语从句要用虚拟语气，即从句谓语用“(should＋)do”。
Our teacher gave us some advice how we(should)use the computer. 老师给了我们一些使用电脑的建议。
(3)名词doubt(怀疑)用于肯定句时，其后的同位语从句用whether引导；用于否定句时则用that引导。
We have some doubt whether they can complete the task on time. 我们怀疑他们是否能按时完成任务。
There is no doubt that Zhang Wei will keep his promise. 毫无疑问，张卫会信守承诺的。 (4)同位语从句与定语从句的区别
同位语从句起解释说明作用，而定语从句起修饰限制作用。
在限制性定语从句中关系代词that充当主语或宾语，有实际意义，作宾语时，可省略。同位语从句中that是连词，不充当句子成分，没有任何实际意义，一般不可省略。
The news that our football team won the match was encouraging. 我们足球队获胜的消息是鼓舞人心的。(同位语从句) The news(that)we heard on the radio was not true. 我们在收音机上听到的新闻不是真的。(定语从句) [即时演练4] 单句语法填空
①The news that he has adjusted himself to the life there makes his parents glad. ②I have no idea whether he will come or not.
③My suggestion is that we inform his parents of this. 三、注意的问题
1．what和that在名词性从句中的区别
(1)what在名词性从句中可充当主语、宾语和表语，意义上相当于the thing(s)that，引导主语从句时，其谓语动词的单复数依句意而定；
(2)that不充当任何句子成分，只起连接作用，无任何意义，引导主语从句时，常用it作形式主语，谓语动词用单数，引导宾语从句时，有时可省略。
2．whether和if在名词性从句中的区别
下列情况只用whether不用if：(1)引导主语从句且置于句首时；(2)引导表语从句时；(3)引导同位语从句时；(4)引导宾语从句且前置时；(5)作动词discuss和介词的宾语时；(6)其后紧跟or not时；(7)后接动词不定式时；(8)用if引导会引起歧义时。
My problem right now is whether I should have someone else take the place of me.
我现在的问题是我是否应该让某个人来代替我的位置。
单句语法填空
1．It suddenly occurred to him that he had left his keys in the office. 2．We must find out when Karl is coming，so we can book a room for him. 3．The most pleasant thing of the rainy season is that one can be entirely free from dust.
4．If you swim in a river or lake，be sure to investigate what is below the water surface.Often there are rocks or branches hidden in the water.
5．The exhibition tells us why we should do something to stop air pollution.