8.  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

此题平行为最大
1. 当when从句/词组没有先行词的时候, 直接修饰主语
参考OG10-.1当when从句/词组没有先行词的时候, 直接修饰主语
occurring when a child…
people when used by …

2 平行：
overestimate the amount of energy used by visible equipment  and underestimate that used by unobtrusive equipment, such as water heaters.
A>n.+ used by visible equipment 和n.+ used by unobtrusive equipment 平行。

3．  单复数一致：
equipment, such as lights, that is visible 。
that 是限定定语从句，不能修饰前面直接接的名词lights.只能将such as lights 理解为插入同位语，that 从句修饰 equipment.