同位语与定于从句

在先行词与从句间加一个系动词，若语句通顺，则为同位语从句，这种说法正确吗

解题思路： 辨析
解题过程：
He gave us the order that we go at once
在先行词与从句间加一个系动词，若语句通顺，则为同位语从句
根据你的意思是the order was that we go at once
根据这种理解也是可以的，同位语从句是对于前面的抽象名词的解释说明
解释如下
定语从句是从句对其先行词的修饰或限制,属于形容词性从句的范畴;而同位语从句是从句对前面抽象名词的进一步的说明和解释,属于名词性从句的范畴?如：
The news that our team has won the game was true. 我们队赢了那场比赛的消息是真的?
（同位语从句，that只起连接作用，补充说明news到底是一个什么消息?)
The news that he told me yesterday was true. 昨天他告诉我的那个消息是真的?(定语从句,news在从句中作told的宾语?)
I made a promise that if anyone set me free I would make him very rich. 我许诺如果谁让我自由,我就让他非常富有?(同位语从句, that只起连接作用，补充说明promise到底是一个什么诺言?)
The mother made a promise that pleased all her children. 妈妈做出了一个令她的孩子们高兴的许诺?(定语从句,promise在从句中作pleased的主语?)
3. 从引导词及其在句子中的成分上区别
有些引导词如how, whether, what可以引导同位语从句,但不能引导定语从句?如:
That question whether we need it has not been considered. 我们是否需要它这个问题还没有考虑?(同位语从句)
I have no idea what has happened to him. 我不知道他发生了什么事?(同位语从句)
引导词that引导定语从句时,在从句中一般作主语或宾语(指物时还可以用which代替),并且作宾语时常常省略?that在同位语从句中仅起连接作用,不充当任何成分,并且不能省略,也不能用which来代替?如:
The order that we should send a few people to help the other groups was received yesterday. 我们应派几个人去帮别的几个小组的命令昨天收到了?(同位语从句,是对order的具体解释,that虽不作成分,但不能省略?)
The order that we received yesterday was that we should send a few people to help the other groups. 我们昨天收到的命令是我们应该派几个人去帮助别的几个小组?(定语从句,是名词order的修饰语,that在从句中作received的宾语,可以省略?)
最后我们在一起来做三道练习题:
1. Along with the letter was his promise ____ he would visit me this coming Christmas.(2004上海春季高考)
A. which B. that
C. what D. whether
2. The other day, my brother drove his car down the street at ____ I thought was a dangerous speed. (2004上海春季高考)
A. as B. which
C. what D. that
3. Luckily,we'd brought a road map without ____ we would have lost our way. (2004北京春季高考)
A. it B. that
C. this D. which
答案:1. B 2. B 3. D
同学：不知这样的解答您能否满意，如有不同意见，请在下面的继续讨论中留言好吗？拾贝老师愿意与您再次进行亲切的交流。匆忙中难免有疏漏，请多包涵哦。祝：学习不断进步， 开心每一天！

最终答案：略