有人习惯根据语感、逻辑词、句意等逻辑关系记笔记。但更简单明了的方式或许是对单句进行有效总结，再加上句间关系的有效发掘。简而言之就是把句子的核心信息+细节信息找出来，理清关系。有了笔记以后，长期困扰大家的定位问题就可以得到有效解决了。

我们以TPO18-3 lighting 中的第二段为例子讲解 一下这种方式：

The separation of charged particles that forms in astorm cloud has a sandwich-like structure. Concentrations of positively chargedparticles develop at the top and bottom of the cloud, but the middle regionbecomes negatively charged. Recent measurements made in the field together withlaboratory simulations offer a promising explanation of how this structure ofcharged particles forms. What happens is that small (millimeter-tocentimeter-size) pellets of ice form in the cold upper regions of the cloud.When these ice pellets fall, some of them strike much smaller ice crystals inthe center of the cloud. The temperature at the center of the cloud is about-15℃or lower. 

At such temperatures, the collision betweenthe ice pellets and the ice crystals causes electrical charges to shift so thatthe ice pellets acquire a negative charge and the ice crystals becomepositively charged. Then updraft wind currents carry the light, positivelycharged ice crystals up to the top of the cloud. The heavier negatively chargedice pellets are left to concentrate in the center. This process explains whythe top of the cloud becomes positively charged, while the center becomesnegatively charged. The negatively charged region is large: several hundred metersthick and several kilometers in diameter. Below this large, cold, negativelycharged region, the cloud is warmer than -15℃, and at these temperatures, collisions between ice crystals and fallingice pellets produce positively charged ice pellets that then populate a smallregion at the base of the cloud. 

根据笔记，其实最重要的一共有三个：

温度低于负15

碰撞之后电性变

风把轻的刮上去

我们根据这个流程看一下题目，你会发现这样梳理完段落之后答题是非常方便的。

3.According to paragraph2, what causes ice crystal to become positively charged?

○Collisions with ice pellets

○Collisions with negatively charged ice crystals at the base of the cloud

○Becoming concentrated in the central region of the cloud

○Forming at a temperature greater than -15℃

4.The word “acquire”in the passage is closest in meaning to

○  reject

○ obtain

○need

○produce

5. According toparagraph2, why are positively charged ice pellets produced in the lower part of the cloud?

○Collisions between ice crystals and ice pellets increase in number in the lower part of the cloud.

○ The lower part of the cloud is smaller than the region above it.

○ More ice pellets than ice crystal sreach the lower part of the cloud.

○Temperature in the lower part of the cloud are warmer than -15℃.

6.According toparagraph2, the middle region of a cloud becomes negatively charged due to all of the following EXCEPT

○a shift of electrical charged between ice pellets and ice crystals

○negatively charged ice pellets that remain in the middle

○a temperature of -15℃or less

○the development of a positive charge at the base of the cloud

7.It can be inferred from paragraph 2 that part of the reason that the top of a storm cloud becomes positively charged is that

○the top of the cloud is warmer than the middle of the cloud

○the middle of the cloud is already occupied by positively charged particles

○the negatively charged ice pellets are too heavy to be carried by the updrafts that move ice crystals

○collisions between ice pellets in the top of the cloud produce mainly positively charged particles

答案是12443

其实阅读笔记过程是可以做为托福听力的铺垫，为托福听力细节题，推断题做好基础的。