一道语法改错题，需求解题思路，谢谢！

cherry0712

1. Lacking information about energy use, people tend to overestimate the amount of energy used by equipment, such as lights, that are visible and must be turned on and off and underestimate that used by unobtrusive equipment, such as water heaters.

 

  (A) equipment, such as lights, that are visible and must be turned on and off and underestimate that

  (B) equipment, such as lights, that are visible and must be turned on and off and underestimate it when

  (C) equipment, such as lights, that is visible and must be turned on and off and underestimate it when

  (D) visible equipment, such as lights, that must be turned on and off and underestimate that

  (E) visible equipment, such as lights, that must be turned on and off and underestimate it when

 

正确的答案是D。

但是我还有一点不是很明白，that后引导的应是限制性定于从句，必须紧跟在所修饰的名次后面，也就是equipment后面，但是五个选项that前面都有逗号而且还有插入语，那五个答案是不是都是错误的？

由于刚开始接触语法部分，做题还是一头雾水，希望大牛指点，谢谢！

后夜

that后引导的应是限制性定于从句，必须紧跟在所修饰的名次后面------这个概念存在一个误区，实际上THAT前是可以插入插入语的，插入语前后用逗号隔开。

语法很灵活，逐步会感受到。

cherry0712

   谢谢：）

   我也是在XDF网上课堂听老师讲的，以后多接触一些题目，感觉可能会慢慢培养出来~